Continuing flight with only a single source of supply on any system is not a good idea. If you are down to one of any of the following, Hyd, Air, Elec, Eng (on a twin) then the land ASAP is a fairly straightforward decision, be it in the Airbus or the Boeing. You will have a hard time justifying otherwise. The APU has the same effect on the equation whichever type you fly.