i could not transition from an ergo 4k to a standard 104 mech(cherry) board. My sig will say that i really love the ergo 4k layout, but of course modding is not for everyone or even anyone (just no time). in that regards i've actually found the kinesis a good 90% close enough to great (of course it could be better, everything can be better).
i wouldn't really recommend the kinesis for gaming, i mean i guess if you switch from WASD to ESDF, it'll work (cuz of the concave it feels weird to move it to WASD), but to elaborate on your original question i used the ergo 4k for 5 years, i've had 2 in the closet in case one breaks and from wear and tear (they break with the simplest of water droplet in them, i've since stopped drinking at my desk anyways). I went to a cherry board, i couldn't do it (no split, slant, all that good stuff), i needed the ergo.