I prefer VX Ace for some things, but game maker for the rest. Making anything where the character directly interacts with something (like talking to an npc), I'd use Ace for. However, for games that don't involve a lot of direct character interaction (like a shooter game, or point and click), I'd use game maker for.
I used to use RMXP, but I always had to recheck the map collisions because of how the maps were done in the engine, and I'd spend more time on that alone than actual development. There were also other issues with RMXP that some users would have, that no-one else would, such as a script hang that I couldn't fix because of not knowing what happened myself. I got tired of the problems in XP, that's when I moved engines. VX Ace's maps aren't the greatest (could've used an extra layer), but they work far better, and I don't have to worry about the player going through a wall that they shouldn't.