All apples to apples the stick is usually better. A 250# weight penalty would be pretty stiff. But in S/SS there are no weight penalties (unless there is in the modified class). There are instances were the index is harder on stick combos. I run SS/G-H-I and the index is only .05 apart per class instead of the normal .015. Another example is SS/J vs. SS/JA. That index is .015 apart but the fastest SS/J will out run the fastest SS/JA on a heads-up run while the SS/JA will out qualify the SS/J.
I think it usually boils down to many of the stick racers are just stubborm and determined to race a stick. Many aren't even chasing records or low qualifying times. But some, like me, are. That's just my bag. Dig it. Groovy....