TBH I'm a pretty big fan of the FCB units, in particular when used in combination with specialized Uno chips. I've got three units, all of them second hand and have played at least one of them for around 10 years both live and in rehearsal with my KPA (yes, I've had my KPA for a while).
True, they are kind of plasticky, ugly monsters but I've never actually had any part break off. I 've had to fix two switches though but considering the wear and tear over 10 years on a unit that was already second hand I consider it to be in the green. I've also modded two of the units (have one at the rehearsal space, one at home) so they have integrated footswitches that connect to the switch inputs at the Kemper's rear. Gives me a lot of additional control possibilities. I believe you can find instructions to these mods either here in the forum or online.
I can't speak much on the issue of accidental presses on the pedals though as I do have quite a small foot...
Anyway, as you can take from the responses above your choice will depend a lot on your personal needs and preferences. If you do go for the FCB I would generally recommend you to get one second hand as they can be generally found pretty cheap. You can spend the price difference on the chip/mods/wireless midi connector etc.
Cheers!