I'll paint a fuller picture to help paint a picture:
We meet in a school auditorium, with a fairly high stage (4 feet of the ground). The school has their own sound system, but as renters, we don't have access to it (or the power that supplies it). We're left with two circuits, one 20amp on stage and one 15amp at the front of the stage. The two spots are roughly 15-20 feet from each other. We usually place the snake near the first amp.
I'd like to keep the two amps on separate circuits, hence the two separate cases. Also, one 6-rack case would be a beast to lift onto the stage (staircases abound), and running power from the front of the stage up to the main rack and then running a speaker wire back down seems less than ideal.
If I was keeping everything together, I would probably go ahead and put the driverack along with it, but since I'll be running XLR's from the snake to both power amp locations anyways, I figure I might as well keep it by the mixing console.
As silly as it seems to have 2U racks with casters, 60 pounds (amp+case) is no fun to move week in and week out. Even using a dolly means we have to move it around on stage. This is part of the reason I wanted a case with a handle, so the racks would be easily transportable, luggage style, but maybe I can use the racks as makeshift dollies instead...
If the subs and mains are anywhere close to each other, I don't see how the speaker runs would be any shorter if the amps were in separate racks. There's room for personal preference in wanting the DSP at the board, I guess, but if you're using it as intended, it should really be a set and forget thing, and shouldn't be a problem to have on stage.
