If you can afford, of course get the D7000 with more buttons to play with and a heavier body to carry around, though the picture quality is about the same as D5100 (same sensor and pixel count) in most shooting conditions.

The D5100 produces noise-free JPEG images at ISO 100-1600, with ISO 3200 also looking pretty good.

If you are like me and enjoy HDR photography, astrophotography, macro-shots and have a deeper understanding of how all the features of how cameras work (like why you would change the metering from "Matrix" to "spot" or why it's useful to change ISO settings all the time, etc) then you will be really frustrated by the D5100 - you are better off spending the money and getting the D7000.

The picture quality isn't necessarily better (although the t3i's larger sensor will show more of the imperfections of a lower quality lens than the D5100's and the kit lens is definitely a low quality lens compared to the other offerings in either the Canon or Nikon line), but the build at least feels better.

I bought the D5100 with two Nikon lenses (18-55 and 55-250 AF-S DX VR Nikkor Zoom lens).

Found this package in amazon.com (Nikon d5100, with 18-55mm and 55-300 mm lens, 32GB SD card, UV filters, wide angle and telephoto lenses) and compared price with Best Buy, Fry's and Costco, Costco was providing the camera and 2 lenses specified above + bag and 8 GB SD Card for $899 but no filters tripods, wide angle and telephoto lenses.

We found that measured ISO from the D5100 is roughly 1/3EV higher than indicated - so ISO 100 = ISO 125 (approx).

While this might reasonably be expected at low to mid-sensitivity settings of between ISO 100 and 800, we were especially impressed with the mid to high settings of ISO 1600 to 3200, where the D5100 was able to retain plenty of detail without displaying excessive noise.

There are 9 ISO settings available on the Nikon D5100 and the ISO speed can be adjusted in 1/3 EV increments.

The good news is that the D5100 performs far better than the Canon in low light conditions.

The D5100 really is amazing in low light conditions.

The image quality in the D5100 is quite incredible up to 800ASA, and rivals the best color films I have shot over the years.

I pair my d5100 with a 55-200mm Nikkor AF VR lens, and with a stabilization rig, quality boom mic, and final cut pro x editing, im able to turn out some stunning and professional video.

The Nikon D5100 brings the high quality 16.2 megapixel sensor, great low-light performance, and full HD video capability with all the frame rate options from the popular pro-sumer D7000 to the enthusiast level model - and then includes a fully adjustable side-mounted rotating screen to boot.

The D5100 boasts a 16 megapixel image sensor (just like the D7000), shoots 4 frames per second in continuous mode, has HD video capability at 24, 25, and 30 fps, and includes the fully rotating rear LCD screen improved in flexibility from the screen of the D5000.