Hi Melissa!
Ah, the age-old stroller question. I think we all contemplate this before every Walt Disney World vacation. My daughter will be four on our next vacation and, like your son, she does not like to use the stroller at home. They grow up so fast, don't they?
Despite her hesitation to use a stroller at home, we will most certainly be using a stroller on our next Walt Disney World vacation. They do so much walking, running, dancing, and playing in the parks! It's nice to be able to give them a place to sit and rest whenever they need it. We especially love it when we're waiting for a parade to start. They can relax in the stroller, have a snack, or catch a few winks. And, if they don't use it, we use it for a place to stash our backpacks, ponchos, sweatshirts, and souvenirs.
If your hesitant about bringing down your own stroller, keep in mind you can always
rent one at the parks or even from a private stroller service. Typically, the private companies will deliver and pick-up the stroller right at your resort and you'll have use of it whenever and wherever you need. Disney-rented strollers must be returned before leaving the rental area.
Overall, I really think it's a good idea to bring (or rent) a stroller for your vacation. It will save you from carrying a tired child and gives you a seat anywhere, anytime.
Have a very magical day!
Ashley