guys, honestly: i don't think this is actually about presets vs fx. i surely could manage to hit first and second row equally well.
i've never heard someone complain that preset 1-5 are in better reach than 6-10 on other well spread floorboards ...
the only exeption maybe tap-tempo which, on a common sense base, should be located at the bottom right.
so for me this is about a footcontroller that is a bit larger, or a footcontroller that is a bit smaller. still: same functionality.
since i want it small, i want fx at the bottom to grant a logical and streamlined layout with exactly no space wasted.
if you want rigs on the bottom, you'll have a 6 switch design with some space "wasted", so if you don't mind hauling around an additional bag for your floor-gear, actually both versions should work equally well. (i still prefer 5 switch-layout for the reason that presets and bank build a more logical block, but this really is just a detail...)
all in all i just want to keep it as small and simple as it gets.