I have had at least 6 Edelbrock 600 or 750 CFM versions and have found them to be a great carb. The only problems that I have had is dirt. Since the carbs don't make dirt, it had to have come from my fuel system. My solution to the dirt problem is to take off the dinky in-line fuel filter and install a professional racer catridge type.
While the Edelbrocks run well right out of the box, to get optimum performance you have to spend a few hours setting up the various spring rates, jets and metering rods - NBD - part of the process of making a performance engine reach its potential. You need the manual choke version of the tuning kit for enough choices
The carbs that I have used have never been affected by vapor lock, but in all cases but one, I had no carb heat (the one exception was on my ancient F350/460cid) plus I always run a 1" phynolic manifold spacer for isolation from engine heat and performance enhancement (dubious value).
Also, many years ago, I ran a 401 cid Buick Carter carb on my
'53 Ford w/312 - an it ran great. My '64 Grand Prix had a Carter as well - and this car was a bear after a bit of surgery on the secondary air operated throttle plates.
To sum it up, I have sold all my Holley leakers but two, and they will be gone shortly. I got tired of screwing around with float levels, power valves, accelerator pumps and secondary springs and diaphragms, plus leaky(air) throttle shafts and base gaskets. I will agree that for full out competition they work well - I really dislike them for a daily driver.