Yah, I have the same basic set-up for my P19MX w/spin using: on top a Harken 3"quad (Nacra?), on the bottom Lewmar w/cam cleat, Yale Conception (Mafioli clone). I note that Karl has oriented the single block attached to the becket on the bottom "ACROSS" the axis of the stack. That is hard to explain to people but is KEY!!! That little trick is the way you get a 7x1 stack to run "cleanly" also.

I used the Lewmar on the bottom mainly because I could get the Camcleat adjusted to the proper angle to cleat/uncleat vs the Harkin "BigBlock 3in w/cleat". I didn't try the Harkin "Carbo's" at the time.

HarryMurphey
H18mag/#9458, Fleet 54
P19MX w/spin /#86, CRAC

I don't see why more catsailors don't use tapered mainsheets. You can make your own, and mainsheets tapered to a smaller tail inside the blocks surely do run easier. Tapering makes Maffioli or its clones really nice.
I struggled for years with fat 1/2 inch mainsheets on Hobies until the revelation struck.