QJs are definitely hard to tune. I am by no means a tuner. I know just enough to make it harder for my tuner to get it back to normal! I have rebuilt many QJs, and they always seem to run well. I don't use QJs on performance stuff though.
Holley carbs are easier to tune, but they have their issues too. Edelbrocks are essentially aftermarket versions of the QJ- bolt it on and go, very little tuning.
Eldebrocks are the Carter AFB clone. I'd warn against the aftermarket or reman quadrajet. Had one that was junk. Got a decent original core and rebuilt it.