For what it's worth I really hate the dinky little F keys on my Kinesis Advantage 2, they're hard to hit, awkwardly positioned and feel gross. F8 and F9 are entirely impossible to hit without moving your entire hand.
I consider this an upgrade. I personally think layer beats any keys I can't hit without taking my hands off home row.
That said my other main daily driver is an HHKB so I'm pretty used to switching layer for F keys.
Personally I would not get a smaller (fewer keys) keyboard if that meant giving up keys like the F1 to F12 keys. I’m fine with having that home row option via layers and Vim and whatnot, but not having normal keys is just a downgrade in my opinion. Some applications want to use funky key combos, and I don’t want to make contortions in order to use them; the key combos might be uncomfortable enough on a regular keyboard where you don’t have to use some “F” key to access something basic like the arrow keys or “Home”.
On the whole the “home row” insistence seems like a bit of an obsession at times. It’s often nice, comfortable, and efficient, but I refuse to believe that anyone ever got hurt (RSI and all that) by moving their hands to the nav cluster every once in a while. (Or else all those piano players must be in some real trouble.)
I like the tenkeyless formfactor. Then I get a standard keyboard minus the numpad. And I can use a dedicated numpad if I need it.
I consider this an upgrade. I personally think layer beats any keys I can't hit without taking my hands off home row.
That said my other main daily driver is an HHKB so I'm pretty used to switching layer for F keys.