Has anyone a lot of experience with PTOs, is this one? Any info on it?

 

Nothing unusual or mysterious about PTOs. I think they all work about the same. Some have spur cut gears and others have helical gears.

 

That's a simple in-out single speed. Usually used to drive a hydraulic pump. The units with forward and reverse are usually used with winches. But as Ray stated, some have straight cut gears and some have helical cut. Depends on your transmission. The used single speed units are worth about $25. The used forward/reverse units are spendy.