Hybrid vigor? The plants we grow are so far removed from wild type cannabis that hybrid vigor isn't a factor. Everything we grow is a hybrid and from a long line of previous hybrids. Unless you're working with original crosses from landrace strains hybrid vigor doesn't enter into it. There are "horticultural" hybrids, like the type we're familiar with, which are crosses of two different strains. People do this to breed desirable characteristics into or undesirable characteristics out of their plants. Then there are "biological" hybrids, which are crosses of two organisms of the same species that have different characteristics due to geographic isolation. Hybrid vigor is only going to apply to the latter.
In regards to the OP's discussion, I move around a lot, so I always try to have a stash of seed to start over from. I pollinate my initial grows and keep the seed, then grow with mothers/clones from then on for convenience. If I'm fortunate enough to stay in one place for a couple years, I'll pollinate again for some fresh seed. In fact I just pollinated my current grow this week (due to a recent move). I ordered seeds last year for the first time in about five years because my stash got lost in a move, but other than that I try to be as self-sufficient as I can. Probably a result of my paranoia more than anything, but I try to keep other people (i.e. seedbanks, the USPS, etc.) out of my garden as much as possible. Coming up on 20 years growing off and on without an incident, so I guess it's served me well.
Oh, I've never kept data in my journals on branching and whatever that other guy said about seeds vs. clones and better harvest from seed, but like I said I've grown with both for ~20 years, and I call bullshit on that. My impression is that yields are (or are potentially) equal. I think people probably flower clones sooner than plants grown from seed because they are able to, that's the only reason I can think of that would lead to an impression like that.
