8. Flying = Impossible
You might think that GTA V's addition of planes as a drivable vehicle has to be counted as a major plus point over GTA IV (and the many, many modders who made it happen in GTA IV would probably attest to that) but the overall flying physics in the game are a step backwards. In both games it is possible to take control of a helicopter, with the obvious addition of planes in GTA V, but the addition of more realistic air turbulence, and the general impossibility of piloting a flying vehicle in every game ever made make the whole experience more of a chore than it should be. Flight school in particular is flat out boring (and it's not 100% clear that you don't even NEED to complete it to progress, which is remarkably frustrating after two hours, a broken controller and several removed clumps of hair.) Okay, so maybe it is easier than in San Andreas, but the turbulence issue might as well be replaced with a giant random Godzilla reaching into the sky and smashing your puny plane of chopper to pieces on the ground, because that's exactly how random it feels. Then of course there are more specific problems with flying, such as the online racing portion of the game that can lead to beautifully stupid moments like this happening...