How good is the Pentax K-R?

In comparison to other entry level DSLR cameras like the Canon Rebel T3/1100D and the Nikon D3100?

Not bad at all. Nikon and Canon command a bigger share of the market these days, but Pentax were making SLRs while the other two were still making German rangefinder knockoffs.

Pentax K-r is much better than the T3, and better than the D3100 in terms of noise performance and speed. Quality is the same on all though.

Here's a DSLR Buying Guide - http://www.the-dslr-photographer.com/2009/11/which-dslr-to-buy/