I used Postality Knight's before. Didn't really seem that glitchy to me. I never once had any real problems with it.
I would not want to pay for an RPG maker. Useually it only lasts for so long for me and then I forget about it and my projects. Besides, I think that RPG Maker 2003 is better than XP. Sure, it looks better and you can use scripts, but I just think that 2K3 is better. Just my opinion on the matter is all.