It most certainly is a good game, but it does have flaws; however, these only affect certain areas of it.
The AI is awful; too slow even on the hardest difficulty setting, and stupid (I just don't play career, even though the structure of the career mode is pretty good).
The handling is definitely on the arcadey side of the spectrum - more GRID than Forza for example. However, this doesn't really notice most of the time; GRID was still good fun, and F1 2010 is still fun to actually play from a handling perspective. It's still very challenging to extract the best laptimes with no mistakes and perfecting all the corners, even if it is within a perhaps less than 'simulation' framework. If you accept that it's meant to be more arcade style than for example Grand Prix 4, then it's still a lot of fun and challenging.
The main fun for me is playing online, especially with friends. The skill spectrum is too wide personally to just play purely with strangers, too often you'll get punted off on the first corner by someone who doesn't understand what they're doing (although this is the same for any racing game really). If you can play with a good group of people though who will respect your car in the game then it is really excellent.
There are a few bugs/quirks still, like the penalty system is sometimes good sometime very unfair, and pit stops still suffer from 'unsafe release' paranoia from your team.
The tracks are very well reproduced, and weather effects are very good and add excitement to races as they should. Tyre wear is another good aspect, and you can actually plan race and qualifying strategies to an extent that will actually make a difference to race outcomes. There are also some excellent mods available that enhance aspects of the game for the better.
However, if coming from NFS Shift (which I thought was appalling, the handling was horrible), I'm sure you'll enjoy it. It is definitely the best F1 game available currently in my opinion, or at least the one I've had the most fun with (playing with friends).
Hope you can get some idea of what it's like from my opinion of it, although it is just my opinion. I think everyone will agree with my points to a certain extent, however obviously it matters more to some than others.
Forgot to mention, also performs very well (as do other EGO engine games). Was running at 1080p maxed out with 4xAA and Vsync and managed to keep ~60fps throughout.
Edited by Scorpii - 6/4/11 at 8:22am