I have gotten so used to having the stroller, that I'm worried about my kids getting too big for them! I love having a place to put our "stuff" ...and it's not just stuff that we bring with us (although we do bring our share of jackets/ponchos, umbrellas, etc.). What about a leftover desserts? Unfinished drinks? Souvenirs? It's nice to be able to put "stuff" in there.
And especially in the warmer months, kids don't want to walk! The heat really can wear them out a lot faster.
We've got a 5 and 6 year old, and we plan on having the stroller with us again in the coming months, but we don't need it constantly - just periodically. We can park it in Tomorrowland and go to the Laugh Floor, Buzz, CoP, TTA, Cosmic Ray's, etc. before we ever go back to the stroller - but then we use the stroller to go to another area... like Fantasyland, where again we will park it and go on several attractions before we need it again. Here I think I've liked the stroller more for "stuff" than for a kid who is tired of walking (though our younger son still naps, so the stroller can be helpful for that too). For just a few hours in MK, we have gone without the stroller and been ok.
I found the extra helpful in AK and Epcot, as those are the places where we feel like we do the most amount of walking - those places are spread out between attractions, and sometimes my younger son will stay in the stroller while we watch street performers in Epcot, or look at animals in AK. He never would've made it walking... and hubby and I have back issues which means we're limited on doing the whole piggy-back ride or sitting-on-our-shoulders routine.
I say bring it!