I recently had the choice between a Nikon D5100 and a Canon Rebel T2i/EOS 550D. I know Nikon versus Canon is many time unanswerable, but I chose the Canon this time. (The T2i was slightly cheaper locally than the T3i, and I didn't see much evidence that the T3i was much improved over its predecessor.)
I know from researching the cameras, that DxOMark rates the D5100's sensor as significantly larger (and, I assume, better) than the T2i's. However, for the life of me, I can't seem to find this difference in the online photo comparisons. If anything, T2i's photos look sharper and richer than the D5100's.
For example, if you use dpreview's "compared to" feature on the D5100 page, the T2i handily beats the Nikon camera on the head-to-head tests, to me, especially in the 100-1600 ISO range. (Was the D5100 having issues during test day at dpreview?)
Similar results (again, to my
eyes) are at Imaging-Resource.com, if you choose the T2i and D5100 -- the the former appears crisper and more colorful:
I'm pleased with my T2i, and honestly I bet I'd be pleased with a D5100 if I had bought that one instead. It seems like most appraisals of these two cameras (or their close cousins) conclude they are essentially evenly matched in terms of quality.
If I had based my purchase on the spec sheet, I would have chosen the Nikon. However, multiple online photo comparisons showed me that the Canon was the "winner" in my eyes. Better image quality trumps all other factors in my mind.
If these cameras are so similar, or if indeed the Canon T2i can be perceived (by some) to take better pictures than its rival D5100, what then is all the hullabaloo about Nikon's larger/newer sensor? I don't understand...
Am I missing something, or is this just an Arms Race with each side showing off larger missile types, while all along any bomb in the arsenal will pretty much get the job done?