Had twin webbers and they were a bitch to tune..... Wonderful when it was right though
The key was getting aero spec lines, rods, joins etc as they don't flex or move much (if at all).
Also had a 350 holley with 500 jets and it was fairly easy to tune
Did it all myself, but got my hands on some workshop manuals to help me the first fwe times... Trying to figure them out without em would've been a nightmare.....
Some of the older jap carbies are really easy to work with as they have less parts...