Honestly, I think stators on warriors are just a gamble. I don't know why, but yamahas, and specifically warriors, seem to have more stator trouble than other machines. Sometimes all you have to do is just look at a warrior funny and the stator quits.
I don't think the stock ones are necessarily crap, because my 2001 still has the stock stator in it, and when I got it the entire machine was pretty well neglected and beat up and the stator still survived. I've seen mixed reviews from every stator out there that I can think of, stock and aftermarket. If it was me, I would probably try to get a used stock one on ebay. I like to follow the logic that if it survived for 15 years it'll probably last 15 more. Usually when I follow that logic I do alright.