You probably get more bang for your buck looking at the G0776 or G0709. The G0776 is a bit bigger, and includes a DRO for just a little bit more. Both have pullout chip treys which are really nice. The G0709 has a universal gearbox, so fewer change gears. They all get positive reviews, both of these seem to have better chucks and a few other items. If I was in the market for a Chinese mainland lathe I probably would give the nod to the G0709, one of the forum member's BGHansen who has one really likes his lathe. You can lookup his posts.
<h1>G0776 13" x 40" Gunsmithing Lathe with DRO</h1> <h2>A precise lathe with a spider mount and DRO.</h2> <p>The G0776 13" x 40" Gunsmithing Lathe with DRO is called a "gunsmithing" lathe because it has features typically not found on standard lathes, such as a "spider" mount system and a large...
www.grizzly.com
<h1>G0709 14" x 40" Gunsmithing Gearhead Lathe</h1> <h2>A powerful, feature-packed lathe designed for extended production.</h2> <p>The G0709 14" x 40" Gunsmithing Gearhead Lathe comes with features typically not found on standard lathes, such as high-precision NSK bearings, extra-large 1-9/16"...
www.grizzly.com
I looked at the G0750G many years ago and ended up with the 1340GT, for me it was more of a quality and finish issue. I had a Chinese mill previously and some experiences with the G4003G and was not happy with the quality. Tough call, the 1236GT is a very capable lathe, more comparable to the G4003G. Three phase motors on a lathe does produce a better surface finish, but there are a lot of other factors that can also effect this. The larger/heavier lathes seem to have less issues with single phase motors, maybe because of the dampening effect of the mass. On the 1236GT/1340GT I have outlined how to do a basic VFD install which is fairly simple, but still adds $500-600 to the cost. Many of the add-ons, chucks, live centers, QCTP that come with the lathe packages are adequate, but the quality can be lacking. The G0750G, I think I would go up a notch. There is a learning curve, and it is pretty steep when you are starting out. Unless you know what you are looking for with used machines, I suggest you avoid that route unless you want to spend your time repairing and hunting for parts.