Well learn something new everyday. Thanks.
I'd say get the AX then
Almost all major PSU suppliers are rebranded OEMs from actual manufacturers. The people who actually make the PSUs you probably haven't heard of most of the time (except Seasonic perhaps). You always need to dig beneath the mask to figure out what's going on.
For example, The CX-400 is a seasonic unit (the X line? Not sure precisely), while the CX-430 is a Channel-Well product. Now even beyond that, you should recognize that CWT is a hit or miss company, they make some good/decent/bad products. For example the GS corsair line is also CWT, but they're fairly crappy low quality units. The HX-1050 is CWT, but actually high quality build, and one of the standards of high power PSUs for years back in the day.
The TX750v2 is a seasonic product, that is actually one of my favs, although it's only a Bronze unit and not modular.