Lost and the Damned is way better than crappy GTA4
why and how
-The most obvious reason is that driving is fun now; the caveat being that the better driving is only with motorcycles. It isn't a big problem since you almost always have access to a bike no matter where you are, and if you don't have one near you, you can call someone to bring it to you. It not only controls better, but you almost never get thrown off your bike. The best way I can express this is that in GTA4 I used a taxi all the time, but in Lost and the Damned, I used it maybe once in the 7+ hours it lasted.
-No more dealing with fickle companions who call you at all times. You can still call them up if you want to play some boring distraction, and if you don't want to, they won't be avoiding your requests (delivering bikes, weapons, etc.)
-Better characters, setting, etc.
-New weapons rock. Semi-auto pistol is like a really accurate SMG, sawed off shotgun can be used on a bike, the grenade launcher is self-explanatory, and the super auto-shotgun pretty much can annihilate any vehicle or enemy in front of it.
-Most missions can only be failed if you die and not because someone out drove you or something; even if you do die, you can restart from a checkpoint (there is a checkpoint after every cutscene.) The average mission here is also far more entertaining than most in GTA4.
The shooting controls are still a bit of a mess, car and helicopters still control poor, and there are a few other problems left over from GTA4, but overall it's a much better game than GTA4. Again, I'd say the biggest reason is the motorcycle controls now.