I didn't much like the demo - it ran pretty well on my PC with no lag or framerate issues, but TBH the cars felt crap. Not that they were slow, but you have no real sense of speed (apparently increasing the FOV to 70-80 fixes this), both cars sounded like someones tapping a can of beans under the bonnet half the time, and leaving out the A.I for the demo was a big mistake without giving it multiplayer. And the physics..meh close enough for fun, not in the same league as LFS but I don't think anyone expected it to be.
IMO every game aimed at online play these days should have a multiplayer demo available, perhaps not as generous as LFS's but I don't spend money on driving sims without trying them online first one way or another. If I want offline I'd rather play NFS than hotlap.
I really hope its not an accurate representative of the final game, it crashed when I went for 6th in the BMW (it only has a 5+1spd, but its a habbit to reach for 6th). The installer was bodged, and who decided its better to set the front/rear up on different pages?