We did 7 night back to backs....well really a 5 night and 7 night thanks to Jeanne, so I can't answer on the 3 and 4 day back to backs, but we reserved the same stateroom for both cruises. We did not have to disembark on Saturday, but we did need to vacate our stateroom for a short period of time so our hostess could do a thourough clean. We left everything in there. We wandered, did laundry and enjoyed an nice quiet, empty ship for a few hours! Lots of great pics from the empty ship. We checked in at guest services at around 1200, but oddly enough, still waited in line for spa ressies!
As far as the repeat enterainment, etc, it was fine with me. They actually switched comedians and there was a different line up for one of the evening shows as well, but since we are not huge fans of the shows, so we saw what we wanted, and missed what we didn't. The one thing that I got sick of was the food. It quite honestly got to be a bit too much and overwhelming after the mid point of the second cruise...some of it is good, but most of it is so, so and two weeks of it was a bit much. I ordered from the kids menu for a change of pace and for some basic food! I'd hate to say it, but by week two, as much as I love Palo, it just was like, "my god, more food???!?!?!" They pretty much just bring things to your table, despite what you say. (But this could be from a full week of WDW prior, so this was week 3 of Disney food.) Things I never tired of...the spa, Scoops, the pool, Fiona in the workout room (Ms. Energy that kept some of the ice cream from sticking to the hips), the Cove Cafe, seeing "50 First Dates" in half hour blocks and sea days. Oh, and one super nice thing is that
DCL recognizes you as back to back cruisers with a card from the DCL president. It is just a nice gesture that they know what is going on.
We loved it, but I think doing 14 days once may be enough for the next few years. (I am still trying to make myself feel better about cancelling the repo!)