I overall think it's an improvement on IV but yeah there's still a few things I hope they fix in the next game
Rockstar really need to take advantage of the genre more. We've got an open world game that fails you if you even attempt to stray from the path. There's no room at all for player experimentation or agency in the story missions
The story for GTAV just loses focus once the characters are all united and just sort of ends with no build up. I remember San Andreas feeling like a damn adventure by the end of the game.
More interesting side content. Stranger missions are fun and it's cool how they tie into the heist missions. But c'mon it's nowhere near as fun as what the old games had. Sometimes it's like Rockstar are afraid of making a video game.