I have two local friends with the ErgoDox Infinity and both are really struggling with the layout.
So a thing I'll say is that every split keyboard is weird in a way, and will require some adaptation. The Kinesis Advantage 2 has a lot of the same weirdness as the Ergodox -- it's columnar; there's only one key to the right of 0 and P, not three; and only one to the right of semicolon, not two. Which means that at least five of -, =, [, ], \, ', and enter needs to be relocated to an unusual place. In my experience (had an Ergodox EZ for a few days now), that's the most difficult part about adapting to an Ergodox in the first place, so I don't think the Kinesis is going to be a big win there.
But like I say, they're all kind of weird. Even the most conventional split keyboard has its unique things to learn: The Mistel Barocco has no F-keys or arrow keys, so you need to get its Fn-key into play pretty heavily. The Kinesis Freestyle Edge is maybe the absolute closest to "normal", but it puts 6 on the wrong side of the keyboard (if you learned to type in the "correct"/standard way), and has kinda weird placement for Esc and arrow keys.
The benefit of the Ergodox is that it is super, super-customizable in a really painless way, thanks to QMK firmware and the excellent online Ergodox-EZ configurator. I set it up initially with a layout that I thought would be sensible and low-adaptation for me (I never tried the default, out-of-box layout even once), and then as I used it and found awkwardnesses, I kept tweaking it up. I've still got changes to make (I'm not happy with where I've got the bracket keys; not a big deal for a lot of purposes, but super-essential for programming), but between adapting to the keyboard, and adapting the keyboard to me, it's getting there pretty quickly.
By comparison, the Barocco's more-awkward programmability was a source of constant frustration to me: I couldn't make every key do what I wanted it to do, and some built-in stuff kept getting accidentally triggered (Fn-A changes your layout from QWERTY to Dvorak/Colemak, for instance, so if I meant to press Cmd-A to select all, but pushed the Fn modifier instead, now my keyboard was in a wacky state; the first time that happened, I didn't even know what I'd done, and even typing in the URL for the manual was painfully awkward).