I have installed 3 of these so far, an Align, a Bestline and something that wasn’t either of those. Two were X axis, one was Z axis.
From direct experience, I can tell you these is not an iota of difference in these units. The instructions are equally deplorable and basically useless. Throw them away and start figuring it out. The main issue that comes up is how many shims to use and how would you know. I’ve tried analytic measurement and trial and error, lots of error. Neither is particularly satisfactory, especially because the criteria for success is not clear. Good luck, eventually you will arrive at a compromise between smoothness and what you hope is minimum wear.
If you are replacing a Bridgeport branded power feed, be aware that, at least in my case, there was a shaft extension required that was something like $120...when it came, I could have made it easily for zilch.
So I suggest getting the higher torque model at the lowest cost possible.