OLED board with tons of options
Very few moving parts
Easy to maintain
Trigger set up can be tricky
Excellent marker for the money. Comes with two barrel lengths and three barrel backs, all the tools you'll need to maintain it and a great COLOR manual. The manual is very good in covering all aspects of the marker from trigger and board set up to maintenance and repair. The OLED board from APE is one of the best I've used. Has all the standard settings (Semi, Auto, Burst) and quite a few more. One of the things I like about the board is not having to open up the grip and moving DIP switches to change settings. The pressure guage in the back of the marker is a plus as I don't have to tip the marker to the side to see it.
If your looking for a marker in the sub $1K catagory that preforms like a much more expensive model, this is the one.