We have stayed at POFQ 3 years in a row now and yes, there are some buses you do share with that resort. Which services and how often/time of day really depends on when you go and what the crowd levels are. You share less often the busier it is.
We found that each resort always had its own bus to MK and Epcot, often shared for AK and DHS except at peak times and we when we were there in September we DID share with POR a few times when we used the buses during the middle of the day with MK.
We ALWAYS shared buses for water parks and for DTD, although DTD does offer the boat service which we found to be quicker than the bus, purely based on frequency and not having multiple stops
The sheer size of POR, which is quite spread out (much more so than the All Stars) makes in necessary to have the multiple stops otherwise if your room was furthest from the main stop you would waste SO much time getting to and from the buses.
We have stayed at ASMu so to give a comparison, I don't think you are going to find you wait any longer. On the plus side, the bus stops at the parks for the moderate resorts are usually closer than the ones for the values so you will save some time there too. You are also closer to all the parks and DTD than you are at All Starts and AKL (with the exception of AK) so you will save traveling time too