We just did 3 resorts in 12 days -- 1 night at BCV in a studio and 1 br lockout (a Sat night on cash,
DVC discount), then 8 nts in a 2br at BWV, then 3 nts at SSR in a 1br.
We tried to minimize the mess by: (1) Packing a single bag for our one night stay and leaving rest of bags in car. (2) Packing up 2/3 of our stuff at the end of the BW stay so we only really needed to open 1/3 of our bags at SSR. (3) Made do without any real groceries until we got to BWV, and tried our best to use 'em up before moving to SSR.
On the whole, ti wasn't bad, but I don't think I'd ever do 2 moves again. Coachsting is right about that "room not quite ready yet" business. Even though we were prepared (we carried a duffle on our transition days that held a change of clothes, bathing suits, and basic necesities so we could fully use pool area, dine out, etc) it still was like a nagging presence -- where is our room? Do we have one yet? We lucked out and our room at BWV was ready at 11 am, but at BCV and SSR, the room was not ready until 4 pm. If I had it to do over -- I would have paid cash for the wkend at BCV, then stayed the additional nights there. We moved to BWV because we could get std view and save pts. Time is worht money too, though, and in the interest in saving some, one less move would have been nice. Plus, it seemed kinda silly to move from BCV to BWV. Same area, really, just a mildly different theme and pool. It seems silly, but the only reason we stayed the one nt at BCV was so the kids could try SAB. We spent both days at SAB, then moved to BWV. All that, just for the pool. And DH and I really felt a need to try BW because we own there since '99 but had yet to stay there (we loved OKW too much to try it, then VWL...) So that's how we ended up with a 3-resort vacation.
Now the move from BWV to SSR -- that was totally different, so it really seemed like a "Change" to us, something new and different. That was really good and I would do it again in a heartbeat -- the kids seemed re-energized by it. I think a move to OKW or VWL would have same effect because they are all different from where we had been at the Epcot resorts. I think it would be hard, though, to go from a DVC to a "standard" resort(non-DVC) -- I'd make sure I put the simple resort room stay at the beginning of the trip, then move to where you plan to stay for the rest of the trip. If you don't do much cooking or snacking (and hence have very little groceries) that helps, but if you do -- try to get by without them until you're at your long-stay residence.
Good luck deciding!