The Gamma X-2 is essentially the same machine as the ATS Super Stringer 2. The Super Stringer 2 is a good, sturdy machine for the price.
The Klipper is a good machine, but it lacks the ratchet/clutch in the tension head, and so is noticably less convenient to use than the others, which have the ratchet/clutch..
Personally, I'd stay away from the e-stringer. Too many stories about the motor behaving badly. Silent Partner's Swing, though, is a good machine that you might want to add to your list.
As for Eagnas... I'll let others tell you.