Those are the exact same fins I got from Dan and they do make the difference. I'm not a deep diver but I do cover a lot of ground sometimes swimming against current. With my old fins ( cressi garas ) after a few hours I could feel some disconfort in my ankles and calves but I've used the pursuits up to 5 hours straight sometimes against current (and actually making progress) and up to 8 hours on a diving day and there are no disconfort whatsoever. The only thing I did to the knive was to grind the point for better penetration for braining fish. Real good gear at a good price.
I did the same thing to my knife.
Only update I have is that my trip to the keys tomorrow has been postponed because of this ridiculus wind, hopefully next week will be better:pray: