Some interesting ideas here. I think the best is just to keep it a standard ram-cart so not to get too distracted. I find it more useful to have a number of carts that I've programmed up, it sort of acts like a library. For example having 5 carts with different sound types, 3 with sound collections. I also use SoundDiver and use floppy storage both of which are very good, but for instant access, usualy for fast auditioning, carts are the way.
As an aside, when I take my SD-1 out the house (gig/rehersal) I always remove the cart as they get stolen.