I have always been interested in Sion since before the rework. And I've always wanted to see the lovable zombie be popular or at least not be so much as a niche pick. So how is the new Sion? Is he OP, UP, or just right in the meta?
What's the scanner say about his power level?
^that
UP, his ult is really easy to dodge and everybody can hear him, and his passive is just useless.
Sion is strong.
The people playing him are just retarded. He has everything in his kit he really needs to succeed, but he does have issues being kited in his passive.
That being said though, I haven't seen a good Sion yet and he's typically banned half the time in ranked because he's new and people will play him for the first time in ranked.
I haven't played a lot of him, but I think hes perfectly balanced (only done jungle with him so far, planning on trying some top today). his early game is a little weak, clear not too good, ganks aren't great but aren't bad either, and Im sure with a little practice you could make them great. after lvl 6 he has incredible ganks, especially post-b-out ganks, and his clear is incredible once you get a 
. Hes meant to be built as a bruiser, a little more on the tank side tho. his passive is getting a lot of complaining but it really is perfectly balanced, easy to deal with most of the time. one of my favorite things about it is how his w gives him a huge shield, and its his main source of dmg despite being magic dmg.
To me he just seems like he needs a few QoL buffs. His passive is junk when compared to Kog'Maw as they have the most similar passives.
Kog'maw does not want to be in melee range at all, his passive makes him run into melee range and attack. Therefore countplay.
Sion takes roughly .5 seconds to transform and begin attacking. One slow from anything, and your passive is useless.
imo, if they changed his passive to being cc immune for the first 2 or 3 seconds, that'd solve a lot and give him a noticeable boost in power.
Other than that, he's fairly balanced and his kit synergy is top notch. His ult is highly mobile, while its easy to avoid the damage if you're quick, it also puts sion into a fight he was half the map away from initially. Its also a great initiate. Think like 
ult interruption.
He lifts
