I have a neutral view towards the Sona remake now that I've tried her; this is a rather personal point of view really, as I tend to play her as a mage in mid rather than a support. She seems less powerful early game because of how close she has to get, Q's 1 less target to hit with, the earlygame nerf on Crescendo's damage (at least that's how it seemed to me), and the lack of any passive auras, but lategame she still hits very hard provided you play your Q's new magic damage bonus with Power Chord right; it only deals about the same amount for a higher required amount of skill, but I'm all for a higher skill cap on her, really.
What makes me neutral instead of against her remake is the more active contribution of her auras and the helpful particle effects that make you tag your auras more easily. The remake has catered her more towards support than mage, unsurprisingly, and I'm just a little miffed on some aspects because I prefer to play Sona as a mage, so I wouldn't really call it a bad rework, just one that I'm kind of meh-ish towards.