Its really got to do a lot more w/ conditioning the skin to take the vacuum. IMO there are lot more things that could go wrong with a BIB than vacuum hanging but blisters are usually the number one reason people do not turn to vacuum hanging. The key is to start slow. Don’t jump up in weight or time too soon. Warm-up and work on attachment technique. Also having added vacuum helps tremendously and I think of it as almost a given. I usually always add 7 mmHg before I attach the weight.
There are things that can be accomplished with a vacuum hanger that cannot be accomplished with a BIB like sets over 20 minutes, or the dual use as an ADS. Its also made my head bigger which was a problem area of mine.
Whatever hanger you use there is always going to be pros and cons. The pros of a vacuum hanger outweighed the cons to me. Just like people have to work on wrapping technique w/ the BIB you have to find ways to attach a vacuum hanger. The way I’ve been doing it lately is awesome. I have zero chance of getting a blister, can take shorter breaks, and hang for longer sets.