[mylesdw]

Too much advance at ANY throttle setting is a disadvantage. That is why these things are adjustable. Production cars are set up with a wide enough margin that a fixed vacuum advance canister is OK. Performance cars running higher compression may indeed experience detonation at part throttle from too much advance using a standard canister, so here an adjustable one is an advantage.

scottj: I am intrigued as to how your set-up works. Do you mean you statically time the distributor to around 35 degrees and have no mechanical advance? I can't imagine how you would start an engine as that is surely way too much advance for cranking.