I actually think it's a pretty lousy game. Same old tired engine, same old tired hiccups that skip 5 frames randomly in a race, same old detail errors all throughout the game (wrong horsepower stats, wrong torque stats, weight etc.). And my God is the "clutch" support in the game atrocious. It serves no purpose at all - even with the clutch enabled and auto clutch turned off, you can still take a hold of the paddles or just shift the knob without ever touching the clutch. To top it all off, shifts are annoyingly slow and delayed no matter how fast you pull them off.
When testing the clutch in the game, I also noticed how if you dump the pedal while in gear without any gas...the car stays on. If you hit the brake, it shuts off for a few seconds...and then comes back on if you touch the gas. Sometimes the cars will stall and other times they won't - it's sporadic. Funny enough, the rate of speed you pick up when just rolling off the clutch is comical, especially if you shift into 2nd and 3rd gear. Realism this is not.
Unlike GT5, the game does absolutely nothing to differentiate between each cars transmissions. A Volkswagen GTI is equipped with a DCT, yet shifts slower than a 92 Ford Tempo, same goes for the GTR. For the DCTs and autos in the game, if you keep your foot down on the gas during a shift, the motor will rev to redline, the revs will drop, and then the car shifts - the problem here is that the game thinks every car has a clutch. If you were to keep your foot down on the throttle while shifting in a manual, the above effect will happen in real life. But doing so in any type of automatic will never prompt such an action.
There's also some pretty comical handling quirks I've come across, among numerous other issues. Simply put, this isn't a sim. It's a neutered racer that lacks a whole lot of attention to detail, which isn't unlike the NFS franchise, so I'm not surprised. The original Shift was a solid first entry, but this one does very little to improve and takes steps backwards in many cases. Many would think I'm being picky, but quite honestly, to someone like me this kind of stuff stood out immediately. Don't call it a sim if you didn't even take the time and effort to get the stats of the cars right - let's start with the very basics...
And boy does the game look like shit compared to GT5 or Forza 3.
Edit: And btw, the cars don't sound anything like their real life counterparts. I had a 350Z, I have a 370Z now, my brother has an M6, friend has a GTI, another a GTR, another an M3, etc...I've driven a lot of these cars in real life numerous times and Shift 2's sounds are simply off. Sure they sound nice and mean, but accurate they are not.