high camera iq guys, wife wants a Nikon D3100 14.2 megapixel digital SLR. anyone have or no if it's a good camera? wife said reviews were good, but when i looked they were very mixed. 
A cameraphone or a toy camera can be a "good camera," depending on the situation and photographer. What does your wife want to do with it now? What has she used in the past? What does she want to do with it in the future?
Reviews are hit-or-miss for helpfulness, because they may be influenced by a factor that's not going to come into play with your use of the camera. A camera that doesn't work well for one person's particular requirements may be the best option for a person with different requirements.
The 3100 is comparable to the Canon 500D / 550D. They're all fine cameras. The differences in specs might or might not make a difference depending on intended use and level of photographer. For instance, a professional wedding photographer would probably prefer a different camera due to low-light performance and responsiveness.
If your wife has big plans for a photography future that might include upgrading the camera body, then that's something to consider now, because she's going to be spending money on lenses, and may want to be reasonably sure that when she upgrades, it will be to a higher-spec model from the same manufacturer, since she'll already have the glass.
If she hasn't already, she should get in and play with the different option in person. Given the relatively minor differences in specs between similar cameras, it's more important to use a camera that you're comfortable using, so you don't miss shots or get too frustrated.
Finally, if she's wanting something she's going to carry around all the time, she may want to look at a more compact system, like Sony NEX or the micro 4/3 offerings. Gives you the advantage of interchangeable lenses in a smaller size.
