Bought one of these last year and have no real complaints. A big plus is that they are made by SpeeCo of Golden, Colorado. They have a customer service # and will talk you through the setup.
The unit comes with two different valve pistons. You use the one that's right for the type of hydraulic system you have. All instructions are included, but changing the piston takes a little time and patience.
With my JD 2240, it's possible to "auto-disconnect" if you fully extend the shaft when operating, so watch out for that. So far, it has split everything I put on it, even 2-3' diameter stuff that I wrestled up to it while it's in the vertical position.
After using it only on the 3-pt last year, I have left the unit standing on its own rather shaky legs this year. Recommend chaining to the tractor if you use not on the 3-pt.