Really depends upon the pleco.
My 14" common likes to hang out on the walls alot. Comes down for feeding
Blue panaque does too, also hangs out on the driftwood.
zucchini pleco does most of the time
three beacon pleco...I have no idea as he hides a lot
rhino pleco hangs on walls.
my old clown pleco just chilled on the bottom and decorations
My old three beacon pleco hid in his cave too and only came out for feeding
so, it really depends upon the pleco, and the fellow tankmates.