Another consideration (for me) is the probable need to leave the equipment set up full time. Don't know if that's a design requirement. But I have a small—albeit well-equipped—darkroom where every cubic centimeter is allocated. Everything has a place where it lives, and back to which it MUST be returned after use, or there will be no more room to do anything else. That's also why replenishment is not feasible for me. Can't really leave the stuff set up permanently.
Space isn't as much of a concern for me, although I would need to remove the unit out of my sink when not being used. I could keep a tank and hose mounted though.