Help, I just can't decide if the more professional camera of the 40D/50D is worth the extra weight compared to my Rebel XTi. Most of my photography is done while hiking & traveling. I love nature and landscape photography. I consider myself a serious amateur, often geting called upon to do friends & family weddings when they can't afford a professional photographer. Also, I volunteer to do some family portrait work outside for low income families. I'm concerned that the 40D/50D will just feel so heavy lugging it on the hiking trails that I'll end up substituting it for my G9 P & S and regret upgrading. To those of you who upgraded from an XT/XTi, has it been worth the extra weight? Did you notice an improvement in your photo's? Is it a much more pleasurable camera to shoot with? Should I sell my XTi and get a 40D, 50D or maybe just an XSi (light but with spot metering which I want) or just keep my XTi? With camera body technology changing so rapidly, I'm not so sure that it is worth the cost of upgrading to the more semi pro camera. Bulky, HEAVY camera....is it really worth it when most of my photography is out in nature and I have to carry it often for miles UPHILL in the mountains? Thanks so much for sharing your thoughts with me.