500D focus issues...
...or rather lack of such
Now that I got your attention, I'm happy to report I'm another satisfied user of T1i.
Compared to my old faithful XT, the 60 mm F/2.8 macro lens got a second life. Focus is spot on - from 1/5 missed focus pictures the number has decreased to something like 1/10 or even lower - and that's because most of missed focus ones were done by "drawing" a camera after running back to catch the subject (usually an aircraft).
Noise: yes, visible - it's something like 350D on ISO200 which isn't particularily surprising given the packing of cells, yet the enormous advantage in resolution makes up easily for this (scale it down, and the noise - or rather grain, given Canon's attention to luminance NR - disappears).
The only thing I'm really annoyed about is responsiveness: with 350D I was most of the time spot on on having "undercarriage shots", T1i is so fast I'm
having hard time getting the moment right.