Me too. Once a rear brake has gone really soggy you'd be there forever bleeding it conventionally.
As for keeping it firm (oooh errr missus etc) I've said it before and I'll say it again: wedge a socket/conveniently shaped piece of wood/whatever between the brake pedal and the frame boss above it and leave it overnight. In fact do that every night.
It does work, really!
I'm sure antonye's right about the 748 brake v. the SS brake: the rear on my 750SS was fine. OK. the disc's 10% bigger but there's a lot more than 10% performance difference!
[Edited on 20-7-2005 by moto748]