This isn’t really an in depth review, more of a quick opinion and some tips on how to use. I hope that doesn’t disappoint.
I recently activated my copy of Color Efex Pro4 and have quickly set about making my own filter recipes. The attached image is an Fw190 A5 of the Flying Heritage Collection in Everett, Washington. I used a recipe I created using Bleach Bypass, Tonal Contrast and Detail Extractor.
This is an awesome plugin. It will quickly multiply the number of “looks” in your repertoire. Be aware that, in my belief at least, all photographers will find some of the filters immensely useful and others completely pointless. Don’t let the fact that you will only use a portion of the plugin discourage you.
Probably my biggest tip is to be sure you are aware that the filters can be applied locally. There are control points within the interface for local control and then you can also brush on the effect through masking. Personally, I use the masking if I want to make sure my entire recipe is only applied to part of the image. I use the control points if say as in the image above, I wanted Bleach Bypass applied to the whole image, but Tonal Contrast and Detail Extractor applied to the aircraft only.
Most importantly, have fun with it.