Can we give Sona either some early game impact or at least more mobility.

Let's not lie to ourselves here, Sona doesn't positively effect the lane phase. You don't have damage to pressure, you don't have sustain, you don't have engage, and your utility is piss poor. To make matters worse, what little damage you do bring to the table is heavily reliant on you getting very close to the enemy. One of the squishiest champions in game, who lacks CC and lacks a gap closer, should not be required to get into 550 range to do the better part of her early damage.

It feels really bad that Sona often takes till level 11, with max CDR, before she starts effecting the game (outside of team fight changing ultimate). She spends so much of the early and mid game just taking pot shots, and healing for tiny pips, and her late game isn't even that good anymore. It use to be great, back when a team fight reasonably took some time to finish, but now you get like 2 rotations and then it's done one way or another. Even when you build her with her "broken damage" route. 400 AP and one damaging ability doesn't hold much of a candle to champions with 3K+ health or do 1500 damage over 1.5 seconds (usually at farther range then you).

Before someone comments about how your suppose to E before going in, please remember that she loses the bonus time on her movement speed if she gets into combat (not takes damage). So you have to pick between blowing two abilities to get in and do damage, OR do damage and get out.

As an aside, i am still convinced that there is some issue with Sona's bonus movement speed. Had way to many games where i have 60+ MS on someone for 7 seconds and the difference in travel distance is microscopic.