As long as you keep a Holley clean they will work fine. Make sure the gaskets are new also. If there is any slop in the throttle shaft that can cause problems too because the butterflies will close differently every time. If you get those things right, and take the small amount of time needed to learn how to tune them, then they are better than all the other carbs. If you are lazy and not too bright than stick to the Edelbrocks, etc.. There is no beating a Holley or their clones in regards to performance and tuning.
Go out and buy a vacuum guage if you don't already have one. Make sure you have the correct powervalve for your engine's vacuum. The Holley site tells you how to do it. Then set your idle mixture for highest manifold vacuum. Your problems with your carb are easy to solve.