Silent,
A bit to general for my tastes.......also every cam system has it's own efficiency levels regardless of single, dual, or hybrid and will react differently to varying arrow weights even within the same cam system.
For example.....you state that duals lose 40-50fps from a 350-450gr jump.
My 03' Patriot Dual Cam did not bear this out.
374gr= 318fps
474gr= 289fps
Net loss over 100gr jump in weight= 29fps. That's 1fps for every 2.9grs
Matt,
That was a pretty generalized statement and I am sure that you would know more about it than me. I was using the generalized 2:1 and 3:1 statement. I actually had you in mind or at least I thought it was you that had previously posted this 2:1 - 3:1 "rule"

. Obviously, it doesn't hold true in every case but generally speaking solos are more efficient than duals.