Coming from shooting on the 5D, which has been tested in every conceivable way, I'm curious if anyone knows what the ideal ISO settings are for the much newer 550D/T2i. On the 5D, the best settings are 160, 320, 640, 1250 etc. Has anyone done or does anyone know of tests on the 550D showing the lowest noise ISO's?

I have read and seen that 1600 is ok, 3200 not so good. But 800 looks good with little noise.

Here is a review with photos showing the ISOs and noise:

Canon Rebel T2i Hands-On Review Photography Bay | Digital Camera Reviews, News and Resources (http://www.photographybay.com/2010/03/02/canon-rebel-t2i-hands-on-review/)