This is an attempt to reprocess a job I did this past summer with the newest version of Photomatix Pro, using the latest Fusion engine. At first I didn't notice any huge differences until I looked a little closer. Seems the biggest thing they fixed the is the alignment algorithm which used to always creates all sorts of softness and 'dreaminess' to images. Clarity increase, sharpness and some contrast bump was how I used to correct for this. The other thing which is somewhat related to the alignment is the Chromatic Abberation correction is definitely improved. I compared this to the last time I processed this job and there were some definite improvements. Microcontrast is definitely more controlled and Fusion is certainly matured a lot since version 3.