[Warspite]

30D is very nice, just been using bosses today which he got over the weekend. LCD is great compared to that on my 350D, but the more practical issues that impressed me was the larger view finder, spot metering, and the means to change ISO in increments. Was also surprised at how light it was, expected it to be about twice the weight it was.

If you can stretch to one, get the 30D - if I was looking for an upgrade/replacement for my 350D I would get that, however it various on whether you can stretch to it, you think you'll use it, and most of all whether you actually like it.

Same advice as most of us would give in these threads is find your local camera shop and handhold the ones your interested in, see how they function for you, what they feel like (in terms of weight and ergonomics).
Then decide which you want.

Personally I wouldnt go for the 20D or 10D unless you can get an absolute cut throat price because although its a great camera, it is also succeeded by the 30D. A 350D is a camera I like, but alot of people dont due to its small size which makes it uncomfortable for those used to more typical sized SLRs, and those with large hands.