If you have the right carb for the right application, that is step one.
Making sure the carb is working correctly is step two.
Knowing how to Tune the carb is step three.
I would never pull a carb out of the box and drop it on expecting it to work the first time. It takes a good 2 - 3 hours to inspect and clean out a carb and I doubt very much that any manufacturer has assembly workers ( someone that actually knows what they are doing) spending 2 - 3 hours on every carb that comes down the assembly line. If they did, the carbs would be a lot more expensive then $400.00 to $600.00.
Even the best Holley carb, has lots of casting seams that need to be pollished or removed inside the main venturies, the booster venturies also have casting seams that need to be removed.
At My cousins speed shop, you would not belive how many folks come in with carbs out-of wack ( not tuned for the engine), wrong carbs for the applications, or just stupid mistakes installing them, having very restrictive fuel filters, tiny little air cleaners with 30% flow restriction...low or unregulated fuel pressure... too many too list.
Also they often think that factory specs for initial timing is their goal, when they put giant heads, with very efficient chambers. Changes all the ignition aspects... every engine is different if it is not factory stock.
2 years ago, I started helping him rebuild carbs for his customers on the side in the busy season... and any carb can be made to run like all the others, if you know what to do to make that happen.