"For the price, nothing could beat it. Nice body, great lense options."5.0 starson by HEVeng
Pros: Image quality, selection of lenses and accessories, size, controls placement
Cons: Canon accessories can be pretty expensive.
Summary: I bought my 20D in February 2005. In a year, I have taken almost 30,000 images. Portraits, car shows/cruises, action mountain bike/trials scenes, landscape...it doesn everything well.
I bought the kit, but never used the kit lense. I sold it unused on eBay. My first Canon SLR was a 300D Rebel and I learned that the kit lense wasn't very good - play I already had 'L' glass.
The Canon 17-40 f/4L is a great all purpose lense with the 20D. I also have the Canon 70-200 f/2.8L, a Canon 50mm F/1.8II and Tamron 28-300 f/3.5-5.6 XR Di. The Tamron sucks.
I spent $60 on the Eclipse cleaning supplies to get dust off the sensor. Easy to do.
The build in flash works good for fill, but avoid it for the primary lighting in a scene. I bought the 580EX flash and it works great with the 70-200 lense bouncing off ceilings.
The 20D battery grip adds more bulk to the camera and keeps the weight balanced. Battery life is extremely good, not that using one battery wasn't good already.
AI Servo focus is sweet for car cruises and the mountain bike races.
The only 20D problem I have had is in going from hot to cold - as in 15F to 70F or vice versa - the LCD goes extremely dark and takes a few minutes to recover.
My carry everywhere camera is a Canon SD550, they work well together.
Canon is supposedly coming out with a 1Ds Mark III this fall. I plan to get one and make the 20D a backup camera.