Greg,
My experience this past season has been similar to what dvw stated about the transition off idle to wot. It works but could be more responsive at the hit. Overall it still was consistent & reliable, but not as good as a holly. This is with 2 eddy 750cfm afb, mod man,493 rb,3700lb auto.Don't know how it would act with your stick shift combo.
Steve

PS- I think the mod man is a good compromise manifold for performance & fitting under a stock hood. Went 10.70's & 80's with a ch-28 & 500cfm afb's 2 seasons ago & 10.40's & 50's last season with the mod man & 750's