Our experience was to always rent the Disney double stroller for our daughter until she was about 7. We would do 10-12 hour stints, arriving in the early afternoon and staying for extra magic hours until closing at midnight or 2am. We'd do the double to carry the backpack with the heavy water bottles and snacks, and diapers etc when she was younger. It provides a great opportunity for the kids to rest between attractions and drink juice/water, snack etc. The only times I found managing a stroller challenging was if we were caught near the parades. Apart from that, as many posters have mentioned, there are too many positives in having a stroller, and different ways to manage by strategic parking locations. Even for your "shorter" days, 6 hours is a long time to handle/carry a 2 year old in hot and possibly wet weather. For me, the potential negatives of not having the stroller would quickly erode the pleasure factor for the child and me (the dad doing the carrying). Whatever you guys decide, I hope you have a great time! With that, if you do decide to forgoe the stroller, I'd be curious to know how it worked out, so please let us know post trip.