I'm still on the fence. I saw & sat in the C8 at Huffines in Dallas (Plano), and it didn't really change my feeling one way or the other. I've been very excited about the C8 except for one major issue: the lack of a stick & clutch manual. I get that the DCT is progress, and maybe once I drive one I'll change my mind, but I love driving a manual (both my 91 ZR-1 and my 15 Z51 daily driver). Having said that, if they do come out with a DOHC engine that revs to 8K+, then I'm pretty certain I'll live with the DCT.
As for fit, I'm not a huge guy (5'10") and I'm used to Competition seats in my C7, so to me the C8 3LT with Comp seats they had felt like what I'm already used to. Personally, I wouldn't buy Comp seats again on another C7 unless it was going to be a track car, and the same is true of the C8. My bet is the base and mid-level seats will be better for most people, and especially for any kind of regular use. The cabin is a little "tighter" feeling than the C7, and definitely more driver focused.
I will say that the secret to the passenger is going to be having the seat all the way back. If you do this, then your elbow will rest just fine on the console. If the seat is moved forward much at all, then your elbow is going to rest on the button stack. This will probably create an issue for passengers like my wife who is barely 5'0" and likes the seat raised up and run forward, but ultimately it's not an issue I'm going to worry about.
Overall, I like what they're doing, but the base C8 with LT2 OHV engine and DCT is not enough to get me to jump. If they don't do DOHC and stick with forced induction LT based OHV engine, I'll either keep my C7 7-spd as a daily or I'll do something crazy like buy a gated manual Ferrari 360 and then get an electric daily like Ford's new Mustang Mach E.