The Good Excellent photo quality; well-laid-out controls; interesting, user-friendly Guide mode; full manual controls in video capture.
The Bad Smallish viewfinder; slower than the competition; no bracketing.
The Bottom Line A very good entry-level dSLR, the Nikon D3100 delivers excellent photo quality in a body that's streamlined for experienced photographers, but relatively unintimidating for the less advanced. Its only weakness is performance; though solid, it nevertheless lags behind the competition.
Until I sat down to actually write this review, it hadn't struck me how confusing the market placement of the Nikon D3100 is. It's priced the same as the still-available D5000, which is in many ways a better camera. And with the exception of video, which many users don't care about anyway, it's very similar to the much cheaper D3000. So while the D3100 isn't a bad camera, and for the most part holds its own against competitors from other manufacturers, it still pales in comparison with its own line mates.
The D3100 has a very good noise profile; it matches (and perhaps bests) the current leader in the budget dSLR category, the Pentax K-x. It produces exceptionally clean JPEGs up through ISO 800 and very usable ones through ISO 3200. (Adobe Camera Raw doesn't yet support the D3100 and Nikon Capture NX 2 doesn't provide sufficiently granular enough noise reduction for me to do raw versus JPEG comparisons). The camera delivers excellent color reproduction in its default SD mode as well--a nice change from some overly saturation-pushing competitors like Pentax and Sony--and its metering and exposure system work reliably and well.