After coming up from the 20D and 30D, the 40D is a great step up. The build quality is excellent, the expos are great improved and the focusing is great improved.
The plastic battery door hinge is a non issue as using the external grip negates that issue.
The camera is fast and the menus are fast. The auto iso feature is nice when in shooting on the fly as in a wedding.
About to buy my second one for my wedding work to go along with my 5D and 30D. Relegating my 20D's to studio work which they are great for..............