It is a personal choice, if you feel your DD needs it, then it's best to use it, especially if it means a happier and more pleasant holiday for all of you

I'm all for that
I suspect I am a bit of a lone voice on this but my dd is now 3 (will be about 3.75 on next trip) and I am looking forward to going without a stroller. Have started doing other holidays without one and I find it so liberating!!! I despise lugging it around (always travel fairly light anyway).
I agree.
We have two girls 6 and (almost) 4.
We went to DLRP this year in May for 6 days without a buggy, we were in the park for 0815 every morning and were on the go all day. Yes, our youngest ended up on our shoulders towards the end of the day, and if were were in the Orlando heat (although a couple of the days were 30c) and staying out late to watch fireworks etc we probably would have hired a double so she could rest.
I do feel manouvering a buggy around the parks and constantly parking it up and looking for it when you exit rides does slow you down. We are planning a three week trip to WDW in Aug 2010, it will be our first August trip and youngest DD will be 4yrs 10months. We are planning three weeks due to the heat so we can pace ourselves, therefore I will not be taking a buggy, but if she really needs one I will hire a double. Eldest DD will be 7 1/2, to be honest she wouldn't dream of getting in a buggy, she is a super fit sporty girl though with a great motor on board!
We also do a few weeks prep for a holiday like WDW and take the girls out for long walks for six weeks or so leading up to it, you can prepare them a little.
To be honest, her first trip there was when she was 19months and apart from a few naps here and there she hardly stayed in the buggy even at that age.