I have flown space - A on c-130's, C-17's and C-5s.
To be honest the C-17 was the best, you just take a blanket and spread it out and watch a movie (DVD player) or read. On the C-5 you have airline type seats, but they face backwards and are not great for comfort.
Forget flying Space -A on the 130, it's NOISY and cramped ... oh, and the seats SUCK.
Oh, and on another note - ever notice the C-5's break down in HAWAII and not Guam, Johnston Atoll, or any other hell hole? And, dontcha know, the pilots coincidentally have reservations on the island for some fun? Not to mention the per diem in Hawaii is higher than most places.
Nice scam for the flight crews ..... "Oh, gee, our next stop is Hawaii, and look, we BADLY need maintainance ... just NOT in Guam or some shithole"
Drove me nuts when I was flying Space-A.