Livinthalife wrote:
So let's talk more about this new AF system. As I mentioned before, I wouldn't notice any difference in the AF since I don't have any fast lenses except the 1.8 which is horrible at focusing.
how many of you are NOT satisfied with the focusing on your XT? I have been more then happy with mine, noticed no problems. Except th e1.8 which everyone knows can not focus on 1 or 2 tries.
Me, with fast lenses and shallow DOF. Things like a 70-200 or the 60 macro can go to pieces on the 350D. Half the time I'm using FTM to 'steer' the 60 macro, and the 70-200 achieves focus and yields OOF shots. Wise POTN'ers said.. "use your 5D you dummy
" and I was enlightened
(and grateful). Dead on focus with the 70-200 now.
That having been said I really like the light weight of the XT, that's why mine still hangs around. It's for those days when I don't feel like carrying the sack of glass like a beast of burden.
The other consideration that prevents me from buying the 400D is that if the AF system has improved so much, think of what the "40D" will bring!
As for the differences.. (my personal opinion, others may see it differently)
- mag body - naaw not really a big deal (350D gets pounded a lot more than my 5D which is treated like it was made of glass)
- faster fps - Could be. If you shoot action this is a consideration, I want 5fps
- less resolution (8 vs 10) - no. My 350D pix look great next to the 12MP 5D
- heavier weight - yes. Would prefer a lighter load on my shoulders
- more shots per battery charge - no. The small battery is plenty, charge it before you leave, and you can carry a couple of them for the size of one BP511A
- 1/8000 shutter max speed - no, not really. I have only used this feature once on my 5D
- viewfinder slightly larger - slightly - it is a fair bit larger. Big viewfinders are SERIOUSLY cool. 
- lack of sensor cleaning - no. Copper Hill rules!! 
- spot metering - occasionally useful. One gets good at 'reading' the XT's exposure program and adding appropriate compensation though (this takes time to develop)
- controls - here I must admit.. the dial is sweet. I love the second QCD and the XT/XTi scores poorly for this..
- potentially longer rated shutter life - if you take less than 50K shots in 18 months, by the time this comes around, upgrade to the 450D 