XP OR SPHERE?

Well, you could always look at various projects on this site that use Sphere or RPGM-XP to see what other people have done with them. At best, you can get a feel for the advantages and disadvantages of each maker is before getting your hands dirty. At worst, you download a bunch of games and waste a mess load of time.

Wait, is that really such a bad thing?

I'm guessing sphere but I've only played games made with it not really used it, X.P might not be as customizable with menu systems and battle mechanics unless you know rgss ( ruby game scripting system ). If you don't mind learning a programing language for this then it could be rewarding otherwise I'm guessing spere would be your best for this...

Is it still an rpg you're planning on making? or are we talking about another genre?

I vote for XP! :-A

If you're trying to do panoramas you can walk on, then I don't recommend RPG Maker XP, because for some reason you can't see them in the editor. Also, RPG Maker XP goes 40 FPS... or slower. It's very resource-intensive for what it does. Your battles in RMXP might be even more choppy than in RM2k3 for this reason.

If you're looking for ease of use, give Sphere a pass because you might actually have to code. I'm not sure if there are scripts already made for Sphere like there are for RPG Maker XP and VX.

EDIT: It turns out there are, and there's a set made to make games like Final Fantasy VI on it. Unlike RMXP/RMVX and the RM2k series, there's no Eventing to fall back on.

What I'm curious about is why not RPG Maker VX? It is capable of using tiles that aren't squarish and characters that aren't squished-looking, that's just a style choice Enterbrain made (a bad one for the North American market, I might add). You can see panoramas in the editor, the dungeon maker seems to be better, and it can actually go 60 FPS instead of 40 or less.

About the only things it can't do are simple arithmetic operations (without a script fix), 3D graphics and more than two layers of maps (three with a "fog" script).

Overall, give them all a try, and see what you like best.

Sphere I should add is not built for RPG's like RPG maker is (hence the name's emphasis on RPG's).

Sphere is like an anvil, so nmost things would be made from scratch. (Whihc isn't that bad, its like saying there aren't any stock systems which most creative types ditch anyways).

Where Sphere fails at is integrating database management with the editor. RPG maker does it better because it focus far more on RPG's and the constituent elements: enemies, attacks, items, spells, players, all of which would need to be pre-considered in Sphere.