I love PathFinder 4, but I have to say other than the ability to have two folder views open I'm somewhat surprised at the upgrade price compared to feature changes. I am certain there is plenty going on under the hood, but I am conflicted with my opinions as to whether I'll upgrade to version 5 or not. Sure I know it has coverflow, but does any one seriously use that outside of iTunes? I still consider it an eye candy and nothing else for the serious user (I consider Pathfinder users to be serious about their file management, which is why they have it). Coverflow is just the latest waste of time craze IMO.
I'll have to give the evaluation version of 5 a fair amount of time before I decide if the upgrade price is worth it. However if you don't have any version of Pathfinder....buy it! Best utility you'll buy for files and blows finder away in about 5 minutes of use.