I've got an 8-speed Sachs but it's just too much. I was averaging about 250 miles between axle breakages. Mind you, I was a good bit heavier then, but honestly, the 7-speed Winner and a half-step + a bailout ring give me 18 out of 21 speeds with no duplication; how much more do ya really, really need?
I will say that the Sachs freewheel is possibly the slickest-shifting cogset I've used.