In all honesty, I never use the 'done' button on the multitasking screen. You can create the same effect by touching any area that is not covered by the thumbnails (ie between thumbnails or on the edge of the screen, or in an unoccupied area). It goes very quickly when I choose to close programs from the multitasker.

TBH, I think I usually do the downswipe closing gesture, unless I intend to close all programs (or at least several of them).

To answer the thread's central question, I don't think anyone's seen enough of Sailfish to consider it, and I don't know enough about that to comment. But with respect to the other options, I would prefer the dual boot.

I really like the swipe UI, and it was a big part of why I got the N9. I have really enjoyed it, but getting a taste of having Android apps work on this device (with apvenv) makes it clear to me that when a flawless dual boot becomes available, I'll be all over it. Though I'd prefer an application compatibility layer that ran Android apps in Meego OS, I think. Performance would be my decision-making factor.

Right now, I'm just waiting for the Nitdroid project to iron out all the kinks, I suppose.