Gain isn't an issue with the Allnics (I have an H-3000). The built-in SUTs add gain to the 38 db of MM input gain, which means at least 70 db for MC carts at the 40x winding.
Allnic's approach is a little different from most phono stages, more like giving the user four high-quality SUTS already on board an MM phono stage. If none of the four is an ideal voltage match for your cartridge, you can supply your own outboard SUT, plugged into an MM input. For example, I use a Bob's Sky 30 with one of my cartridges, not because my Allnic doesn't supply enough gain but because this cartridge happens to love a 30x winding in an SUT, whereas Allnic supplies 13x, 20x, 26x, and 40x. The 26x and 40x sound pretty good with it but 30x sounds even better.
I've never heard the Zesto but I know several people who really like it, even up against more expensive pieces like a Steelhead. I owned a K&K Maxxed Out and liked it a lot but sold it in preference for a Steelhead, which was, in turn, dramatically outperformed by the H-3000. That's not to say the H-1201 is in the same ballpark, though.