Well, I just got done playing it for roughly an hour, and I gotta say, the gameplay is quite involving. You really have to do quite a bit more in this game than in the previous CMS games, even for the simple tasks at the beginning of the game. One of the first jobs involves swapping tires, and you actually have to use a tire machine to separate and reinstall tires, and you can't put them back on the car until you balance them on the balancer.
It's not perfect, though. The tutorial doesn't really teach much, as you basically walk through a max-level garage to see all the tools available. It's also extremely graphically demanding on GPUs. Even with my RX 480, I gotta turn down the settings to Low to get anywhere near 100 FPS with only one car in the basic garage (since I play on a 144 Hz monitor), and it basically maxes out my GPU, ramping up the fans higher than any other game I play. And mouse acceleration is annoying, and you can't turn it off (yet).
EDIT: Plus, 10% off sale with 10% off coupon for owning CMS 2015 is really nice