And as to the issue.
I dive doubles whenever possible. At first, it felt like I was carrying the anchor for a largish yacht around on my back. But seriously, this gets better, to the pont that you don't think about it. The continuing issues for me are bouyancy control & at deeper depths, staying out of mandatory deco.
Doubles may not be an option on most dive charters. At 100', I am wanting some kind of dependable redundant gas source. A set of doubles, a good KNOWN buddy, or a bailout bottle, all could count as such.
There is a very short list of buddies that I would even consider doing penetration dives with while wearing a single. If you gotta ask, you ain't on the list.