I have been playing with this program for about two weeks, and the more I use it, the more I like it. My standard raw convertor is Capture One 7, although I use RPP for selected images. PN almost always produces more pleasing, natural looking images than C1. Colors have long been C1's greatest strength, but I am getting better colors from PN, even though it does not have a specific profile for my camera, a Pentax K-5, and that should be fixed soon. Detail and sharpness are excellent. Exposure and brightness are handled very intelligently and flexibly. I have read in other threads that some users feel that they can get equal or better results from ACR/LR, which is totally opposite from my own testing, and I don't think that it is even close. (I will not be posting comparative samples, so just accept my opinion for what it is--my opinion).
To be sure, Photo Ninja has a quirky interface that requires more steps and clicks than one would desire. Also, it is lacking in many features, including curves and levels, that are found in other programs Nevertheless, the results are so good that one wonders if PN's designers have found ways to work without them. It has no cataloging feature or local adjustments either, which will bother some, but not me, as I prefer to do local adjustments in Photoshop. Picture Code has stated that the next upgrade (v1.1) will be available as a Photoshop plug-in, which will certainly improve the workflow.
In any event, Photo Ninja is worth a free trial. Just understand that the trial version will not process images. For that, you need to purchase a license.