Overall very good in my view. Good looking despite hard touch plastics; having the center storage console relocated to above the glove box is extremely convenient especially in this day and age of USB connectivity and it opens up an extra cupholder, also very useful; doors open really wide which is great; good cupholders; a sense of spaciousness in front you don't often get; wonderful steering wheel, finally a company besides Toyota that understands the comfort of a thick steering wheel rim, Mylink system in Sonic is much better than most touch-sensitive ICE. Here's what I would change:
DIC on dashboard should be larger and have a couple more mode shift settings on the stick, to allow room for display of things like coolant temperature and tire pressure. But keep the digital speedometer; it has already prevented me from getting speeding tickets, I am absolutely convinced of that.
Plastics should be overall slightly thicker, and more tightly fitting, to cut down on rattles
Dynomat. Yes, I know it has more noise insulation than the Euro version or most other cars in its class, but it could use more still. This also might enable them to get away without thicker plastics from a rattling standpoint.
Armrests. Door rests should be padded; driver's rest should be an inch or inch and a half lower, or, better yet, adjustable.
Seats. Seat base cushions should be firmer, especially on the cloth seats. Front seats should be set higher which would improve legroom and visibility and give the back seat a little more space. LTZ leatherette needs to be replaced with the real thing, or a better fake product. Head restraint angle should be adjustable as not everyone likes to lean back at a 35 degree angle. If raising the installed seat height is not realistic, then bring the electric height adjustment over from the Cruze as it allows the seat to go straight up rather than up-and-forward, an important consideration for legroom.