I noticed the same thing with DS4, after I was switching between FC and the DS, I noticed the FC4 had faster response when trying fast combos, plus bigger buttons for the Hori makes you switch buttons even quicker.
for the meantime, I kept the controls of FC4 as default for 2 reasons, the R2 (blk) button for the enhanced moves, and because most of combos that people write online use 1 to 4 numbers, or just triangle / square etc. and I'm used to terms as HP / LP / HK etc.. and need to re-translate the whole moves for the new buttons setup again.
So I thought maybe someone who's an old school player went through this as well when using the R2 / Block for EX
I've seen too many reviews for the PDP, and you are right, its reviews are garbage.
some of the most FC4 reviews say the pad is bad too, though I think the users are harsh when using the pad.
My Sega Pads which came with it, never been changed, nor have been damaged, although with excessive UMK3 playing back then.
And I've seen how a lot of people use their pads, and breaking the shit out of them lol.