The point of a series

I finished the main narrative in GTA 4 over the weekend. And I know it's good and all but I can't help but still have this strange feeling of let down from it all. The driving mechanics and physics have changed to make the whole process much less enjoyable which in turn makes the radio much less enjoyable. And those two things are the heart of the series for me. But let's not also forget that they moved away from having any celebrity casting, limited your clothing options without improving that clunky store interface at all, removed all silencers, removed the "skip the car ride" option to streamline missions, stopped the tradition of having a carry-over character in mission critical cutscenes, took all the fun out of driving the motorcycle as the merest hitch will cause you to fly 80 feet due to their crazy rag doll physics engine, took out the bike and airplane vehicles, turned the standing gun gameplay into paramilitary duck and cover rather than just fun old run and gun, no driveby camera angle, etc

It just feels a bit too different from its predicessors.