First off, APE's "Rampage" board and 7th Element's "Pathfinder" board require different grips, as their OLED displays are different sizes, and in different places.
The APE board has a display that is bigger, and displays more information than the Pathfinder board. Compared to the APE OLED display, the 7th Element display seems small.
I believe that APE's programming is head and shoulders above everyone else's, and should be the deciding factor when looking at an aftermarket board. I think the APE "Rampage" board is truly an upgrade, whereas the "Pathfinder" board doesn't seem to do much more than the stock DM board from a programming standpoint (if someone thinks I'm wrong, please explain how).
The APE board will never become obsolete, because the tournament modes can be changed by simply turning on the board and going into your programming mode. Your Rampage board will never need to be sent in to be "reflashed" due to changes in the tournament modes.
Additionally, the APE board comes with acrylic grips made by Stinger Paintball Designs (SPD). You can buy your APE board with the "Rampage" grips, or you can buy your APE OLED board without grips for $10 less, and have custom grips made for your marker by SPD
with a design of your choosing.
This is my opinion, and you made the right decision to ask around before making a purchase. It's best to be well informed before making a purchase like this.