Upgrading from XTi to a heavier camera like 40d or 50d....

[photog4fun]

 Help, I just can't decide if the more professional camera of the Canon 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.  My photography hangs on my home walls, usually 11 X 14's or 20 X 30 enlargements.
 I'm concerned that the Canon 40D/50D will just feel so heavy lugging it on the hiking trails that I'll end up substituting it  for my Canon G9 P & S and regret upgrading.
 To those of you who upgraded from an XT/XTi (or similar weight dSLR), 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 but size & weight is my main concern.
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

[Bob Atkins]

The weight difference isn't huge. The XTi weighs 18oz while the 40D weighs 26oz. So the difference is 8oz which really isn't a lot.

Why do you want to upgrade. The difference in image quality will be small. The 40D/50D are nicer to use, but if you are happy with the XTi you might better spend the money on a lens or flash.

When I'm hiking it's not so much the weight as the size. I will sometimes take my A720is simply because I can slip it into my pocket. There's no DSLR and lens you can put in your pocket. A G9 (or possibly a G10 soon) might not be a bad idea if size and weight are critical. The G9 has been listed as "discontinued" by some stores and is out of stock at others, which might suggest that a replacement is coming!

[lukeap69]

I just upgraded from XTi to 40D and for me the handling is much noticeable. I normally shoot manual and the extra dial for the aperture is one of the deciding factors for me to switch besides the built and better viewfinder. IQ wise, there is not much to desire although I find the ISO 800 and 1600 of 40D better than XTi. Weight, 40D is heavier but I prefer that over the weight of XTi.

If you are happy with your XTi and can do the job for you, I do not think it is necessary to switch.

[mijm]

I have the xti.  Along with that I have the Canon 24-70 L 2.8  and the Canon 70-200 L IS 4 lens. Both the lens are great. Lens sure make a difference. Both are heavy, but if you want good pictures you have to spend the money on lens. Save your money and buy a new lens.