I bought RMXP when I was 12, but haven't ever used VX for more than half an hour... But it's pretty similar and both XP and VX have Ruby scripting capabilities. Ruby is pretty easy to learn and you could do a lot of stuff with it, really fast. It's faster than creating everything with cumbersome events. VX has a good framerate and is more efficient than XP iirc, if that matters. I used 2k3 too, which is good if you don't mind that the only translation is "illegal", which has built in side view battles and stuff.
I always wanted to create an rpg for the heck of it in rpg maker because it's simple and fun, but I got carried away with the ruby scripting and now I just code straight ruby, ha.
I always liked 2k3 for reasons I can't explain in short, you should try it out and see how it likes you. : D