I've been playing for many years as a lead jazz big band player and am very acquainted with trumpet stuff, but i ran into something i just can't figure out. Ive been playing on a $2000 getzen 900S eterna classic for about 2 years now. but summer of 2010 i picked up a new used horn for $200 that is in considerably worse shape (the valves are pretty crappy and it's an intermediate level jupiter) than my expensive horn. lately, as in almost always, i have been playing the jupiter, and have been playing to the fullest extent of my skill. but now, when i play my getzen, I get burnt out within half an hour of moderate practice, much easier practice than i would with my other horn, and cannot reach the top area of my range. that's my problem; i perform worse with my better horn, and better with my lower-quality horn. can anyone explain what could be the problem? thanks in advance. also, if im performing better with the jupiter, the logical thing is to use it more. the only issue is the valves are super sticky. with many cleanings and oilings and wiping the oil and re oiling, the y still stick. any suggestions? should i get em acid bathed?