I played a few quick races. From what I can tell, it looks/feels exactly like last year's game, but the simulation mode (no stability control) is actually playable now and feels pretty nice. I ran a few races on the regular "out of the box" settings, the only changes I made were race length (bumped from 3% up to 4%) and AI difficulty (auto/regular bumped up to auto/hard).
First race was Cup at Atlanta, driving as Chris Buescher. 13 laps, started last. I was WAY faster than the field, I basically screwed around and even spun out at one point when I intentionally wrecked someone, but still had more than enough time to race to the front and easily win. Ridiculous. My "speed rating" was 100.
Second race was Xfinity at Iowa, driving as Daniel Hemric. 10 laps, started last. I struggled to finish 38th....seriously, the settings were exactly the same as Atlanta, but I only passed two cars this time. I noticed the same thing that pissed me off in the first game at some of the faster tracks, the auto braking (part of the stability control, for whatever reason) totally ruins your corner exit and kills your speed. I got 38th out of 40, yet my "speed rating" was still 100. Weird.
I did the exact same race again, but this time with no stability control, and raced up to 27th. It felt a lot better without the stability/braking BS.
Next, I raced the Trucks at Eldora as Spencer Boyd (#12 truck). It was only 6 laps, but it was a lot of fun. I raced it twice (one with stability, one without) and raced my way up to the teens both times (with "Speed Ratings" of 98 one race, and 96 the other). It was fun with the stability aid, but it was even better with stability off.
So, my first impression is that the game is very inconsistent with AI again (no surprise there) but I think online will be even better this year with the additional series/tracks. My only concern is that online mode forced you to race with stability control last year, and I feel like its probably the same again this year. If so, that's disappointing.