It really depends, and is up to you. We used to live down in Florida, so taking midday breaks wasn't one that we'd do, obviously as it was too far, but what we DID do:
-Rope drop to shortly after Fof parade finished, SOMETIMES, we'd wait for Hoedown or 5:40pm MiSi to be done, and then we'd head over to Trader Sams or the Grand Floridian, grab some food, have some wine, enjoy the a/c for a few hours, usually spend 2 hours, maybe more if we had a sit down meal, at the resort, and head back into the parks for Wishes/Dep. It was always nice to take a break and get out of the park during the busiest part of the day since there's all the day people, and all the people who are just coming in for the evening.
Midday breaks DEFINITELY help keep you going in the heat/crowds/whichever, it's nice to take that break, 2-3 hours isn't a lot at all, esp if that includes transport back to the hotel. Also think of it this way, if you're ONLY spending an hour at the hotel, do you sleep the whole time, swim the whole time, just relax and eat? or try to divide it up? When you give yourself a few hours you have time to do it all.
I usually work it out so I'm not taking a break every day when I'm on vacation, I'll do rope drop to wishes at MK,(using things like, meals, Caroseul of Progress, Country Bears, Tiki Room, Hall of Presidents for a/c breaks/naps) schedule a break on DHS since it's lacking options, and AK USED to be "do it all by 4pm, then have a resort night" now I'm thinking I'd do as much as I could by say, 2pm, then head back for a break before the evening festivities. Epcot's a chill park for us, and you've got a couple of options to take it slower/use the a/c there, plus when you're wandering world showcase there's lots of shops to jump in and out of and shows to kinda slow down to watch