Jazz was at one time Standard,but it is now Preferred along with Calypso.ASMu does have the worst layout for walking times. We were in the Country section (the furthest section) last August and it was rough on me because of my mobility issues. ASMu is the place where you want to pay for preferred rooms, IMO.
I would request Jazz Inn if I was in a standard room. It's the closest building with standard rooms according to Touring Plans.
Over at ASMovies, though, the layout is so good that nothing is really too far from the main hall. Over at Movies, if you were put in one of the Mighty Ducks buildings, it's actually closer to walk over to ASMu for their main hall and buses.
I've never stayed at Pop, but I've been over there a fair amount of times while resort hopping. Although you don't have the Skyliner, the food court does open at 630AM instead of 7AM, which for us is a benefit over Pop Century.
And in addition to the 6:30 AM open for Intermission Food Court,unlike at Pop Century,the Beverage Island is accessible 24/7 for Mug Refills.