Most say you'll have to slip the clutch a little more than with steel when starting from a dead stop. Others say they hardly notice a difference. I'm sure it differs from car to car (different wieght vehicle, gearing, cam, etc.).
The Fidanza (sp?) aluminum flywheel has a replaceable friction surface. I would assume the durability would not be an issue
I plan on buying one through Brian at AD Performance. Best price I've seen.