any opinion on barry grant speed demon carbs

[jon79flavette]

I am going to replace my carb, I am looking at the 750 speed demon barry grant carb. has anyone used these, how does it compare to the holley 4779 doubble pump (mech secondaries)

 

[silver 80]

I've got the creat demon but haven't put it on yet, maybe a winter project. I bought it to replace the Q-jet but I had the Q-jet rebuilt and now it screams.
there is someone here that put a Demon on try doing a search.
tom