I'm doing my restoration with the Frame On on my Argosy 26', as I was worried I'd end up with a leaky shell if I took the Shell Off. It's still a work in progress but I've almost got the frame cleaned up and floor back in (It's partially installed).
Now that I've removed the interior, the floor, the pan, the belly wraps, removed rust on floor, replaced plywood in a c-channel compressed by the shell's weight etc, I wish I'd taken the shell off. If I had the shell off, it would have been so easy to bead blast the frame, flip to remove the pan etc...Still a lot of work, but I have to think it would have been less work than the way I did it.
You can do it with the shell still on, but it is a royal pain in the keister. If there ever is a 'next time', I'll be building a gantry and lifting the shell off.