If you can go to some local shop and play with both the 40D and 50D side by side, then I think that's what you should do since 40D vs. 50D is a very very tough question - I personally went with the 50D eventually, but I couldn't find a shop which let me compare them both side by side - I could barely find a shop who let me play with a working (battery + CF card inside) 50D, and couldn't find any shop with a working 40D.


If you have any questions regarding the 50D, I can help a bit I guess.


Also make sure you see Bryan's latest high ISO comparision - especially 500D vs. 50D.