I have done both off and on. My family prefer off, but me being the disney freak, like both. A few years ago, we stayed at POR. I loved the theming etc and the feeling of being "inside disney", however I just could not stand listening to snoring all night, being crampt in one room and hearing noises all round our room. I hardly slept a wink. The magic was lost instantly with me.
Our next trip will be with our DS2 and I can not imagine anything worse than putting him to bed in the same room as we will spend the rest of the evening.
Our last trip was offsite in a beautiful 4 bedroom villa in Kissimee that cost less than staying in all star resort. We felt right on the doorstep of WDW and It was definetely quicker geeting to the parks then when we were onsite. We had our own pool, bedroom, living, dining space and that was worth sacrificing the odd perk onsite.
I guess weighing it up I prefer off