Sona rework - a stand-alone analysis
Managed to get four games in on Sona in ranked play. Not necessarily the best player, nor is the sample size that large (I intend to try her a few more times) but what I've seen in game pretty much solidifies my opinion on why I feel that she's changed from a fairly competent spell spammer with a bunch of decent persistent buffs into a mess of various abilities and characteristics that don't mesh well together. I'm not going to try and throw any old vs. new comparisons, calculated math, etc. and will mostly focus on reworked Sona as a champion in comparison to other supports currently available to play. I'm more concerned about the viability and logical gameplay of Sona as opposed to any fun aspects related to her, so if you're more interested in discussing whether you find it fun to run around and tag allies, this isn't the discussion for you.
In general, Sona's abilities place more emphasis on tagging allies with your auras as opposed to casting them for the base effect that occurs. As balance seems to be more adjusted for the auras, the base abilities themselves aren't that strong. Aria of Perseverance is the exception to this rule, being able to heal for a considerable amount to wounded allies, but even then, the AoE shield is too good to be sitting in the backrow.
As a damage spell, Hymn of Valor is undoubtedly one of the weakest spells in the game. 40 damage at level 1 is exceptionally puny and the rank 5's 200 isn't any better, especially when spells that get this low have significant special effects, such as Zyra's Grasping Roots (E). Hymn of Valor does have the benefit of being a pseudo-targeted ability but 650 range puts you at a lot of risk for too little damage. The aura that grants bonus damage (20/30/40/50/60, up to 90 with rank 3 ult) can supposedly make up for the damage lost on the active component, but as auto-attacking isn't an instant activity, you're bound to eat a spell or an auto attack that deals similar damage back. As this is her best ranged damaging spell that is not her ultimate, Sona's on the low-range end of the support harass spectrum. Due to the nature of the aura, you often need to make a choice between giving your AD Carry the additional damage and sacrificing the active damage, or going for the Q-auto harass combo but not being able to grant your AD Carry the aura. With enough coordination, this can be alleviated, but it doesn't change the fact that the only reasonable period where you'll benefit from both parts is when late game rolls around (when your active component is completely ignorable anyways).
Aria of Perserverence is a decent healing spell, but cannot be used like a standard heal. It's best used when allies are considerably wounded, especially at earlier levels where the base value is only 25/45. Aside from the first few ranks of the ability, this is a relatively decent spell whose high mana cost is offset by the fact that you shouldn't be spamming this ability until late game when you have the mana regen to do so. The shield aura is arguably the best of the three, providing a strong shield that, with high or max CDR, can be up often enough to mitigate a lot of damage over time. There isn't a lot to hate about this skill as it's useful throughout most of the match.
Song of Celerity is an admittedly weak spell, though it's in a better position than Hymn of Valor. It's main use is to give you a burst of movement speed to aid in tagging allies with auras you desperately need to give them. As a one-point wonder spell you'll likely pick up at level 3/4, it's not bad, but the 12 second cooldown (7.2 seconds with 40% CDR) makes it difficult to use early on. Of the three auras, it's arguably the weakest though again, it's more for Sona's own personal use. If you manage to play AP Sona, it's much stronger and is essentially Karma's mantra-E on a much shorter cooldown.
As the ultimate has not changed, I won't be discussing it. You wanted to level it at 6, 11, and 16 before and you still want to do that now. One comment I will make is that for an ultimate, it seems exceptionally small. A 1.5 second stun is still strong, but most other commonly used supports have a very similar option in their kit that's either an overall stronger ultimate or a base ability that doesn't use up the ultimate slot.
Her passive as is is inappropriate to her playstyle and her cooldowns. Early game, Sona will find it difficult to cast spells in such a manner that she benefits from both parts of her abilities. With this in mind, she'll be spending 135-270 mana (depending on combination of spells) just to get one of these bonus effects. Late game, you'll either be stuck on the 50% damage bonus due to the flow of Q-auto, or the slow. In either case, you'll have to get within 550 range to use it, which puts Sona in a compromising position due to her near lack of innate survivability.
Overall, Sona's influence across a game only gets better as she manages to get the items and levels she needs to make her abilities stand out. CDR allows her to constantly keep up auras on her allies and they'll be able to make some impact.
The problem comes in getting to the late game fantasy. Sona's early game is quite atrocious, more so before level 6 where your auras aren't nearly as strong as they could be and your base effects tickle at best. In one of my games, I had to go through the unfortunate ordeal of being completely shut out by a Janna, whose shield pretty much nullified the better majority of my combos. If I did manage to get something through, the damage was small enough that a few hits of lifesteal pretty much threw me into a mana disadvantage. Once Sona hits 6, the presence of the AoE stun makes it much easier to pull off auras on your AD Carry, but for what it's worth, it's only an additional 50 damage on your total burst.
Mid game, teams are starting to group up more, allowing for Sona to focus more on tagging and allowing her allies to do the work. as Sona is practically always front or middle line, you're putting yourself in constant danger of eating whatever AoE effects are going to hit the allies you tag. With W, this can be worth it, as the shield + heal can eat a good portion of the damage. The easiest way to get the auras off is to obviously group up everyone into Sona's radius beforehand, but this opens up a lot of potential to get wombo combo'd, and isn't advised. When you throw mobility into the mix, Sona will either require some coordination to work with, or will practically be useless because she couldn't buff Lucian's next auto-attack before he dashed out of range. This pattern continues for pretty much the rest of the match.
While I found it fairly easy to tag multiple allies, seeing the effects in action was a different story. I only ever found the shield noticeable, especially when it would at least nullify some auto-attacks and abilities. The haste never seemed to speed my allies up that fast, and with the bonus damage aura, I found that it was essentially a waste of time trying to tag everyone when only three people (including myself) ever used it consistently.
As your role is to constantly tag allies for auras, you're pretty much always in constant danger, yet Sona has low base health and low armor. The shield helps to mitigate this somewhat, but if you're ever caught, you'll either die or be forced into the backline, where your effectiveness drops drastically. Put simply, Q and E do not provide enough notable benefit to justify me putting myself in danger. Problem is, I have to do it anyways, because Sona doesn't have a lot to offer otherwise. Of the viable supports, Sona's weaknesses are pronounced enough that she's actually hampered by them on a regular basis. You know how Ashe is considered weak because she has no reliable steroid or mobility? Sona's like that, except it's a lack of non-ult peel and independence.
Overall, if I had to state what Sona brings to a team that other supports don't, it's that she has a spammable AoE shield mid-late game and a decent AoE stun ultimate. Problem is, these two components alone are not enough to make her pick-worthy. Her AoE stun is easily replaceable and her AoE shield is only decent at best compared to current bottom lane support terrors who can either harass much better than Sona can, can delete her with more damaging spells, can get the jump on her with gapclosers whenever she attempts to harass, or a combination of the above. Should she be kept in her current state, she needs quite a few tweaks to her aura radius, base stats, passive, and some of her aura effects before I'd even think people would consider using her seriously. As is, she only felt like a relevant pick in the one game I ended up playing a solo lane with her (team miscommunication), where building a large amount of AP actually made her pretty formidable, even though she still hates being in the front line.