I haven't used one of the entire carbs, but I have used some of the individual parts on other carbs (metering plates, main body, and throttle body) and the parts worked well. I like the adjustability of the screw-in restrictions in the metering plates.

As for carb size, the 750 is fine for street driving.
I had a Holley Avenger 770 on my 505" stroked 440 before changing to EFI. The 505 is a street engine with a mild cam, comp XR286HR-10 (236/242 duration @ 0.050")
The car was only slightly quicker at the track with the EFI compare to the 770 cfm carb.