I have a sump set up with diagonal filter media.
A lot of crud builds up on the bottom of the sump, but otherwise it works just fine.
I have the medium-fine poret material, and some finer sponge media in that sump.
Flow is great. No need to divert it to spread it out. If the media gets plugged in one area there will be more water flow in another, until that gets plugged.
It takes so long to plug up the poret or coarser media that there is not benefit to running it diagonally, though.
If I ever rebuild the sump I will do it the traditional way, with the media at right angles to the sides of the sump.