Of course I use all 7!
Sorry didn't mean to imply *you're* only using six strings. That would be rude and condescending. (Unlike when I insulted your fingers hehe.)
The times I've played sixes (not that often), they were noticeably easier to control and I thought I'd stick with that if all my compositions didn't already use that 7th string.
Ok that's a rotten lie, I was in love with the 7 string concept from the moment I first laid eyes on one. ?
I don't know about resonate and sustain etc. I don't really think there's that much difference. Maybe you're right.
I'm kind of away from the whole basswood thing, which is the main reason I don't play my UV that often lately, not for serious work anyway. It's in the lounge lately as the in front of the TV practice guitar.
The J Custom and Dean RC7, both mahogany, both sound better in my current-and-liable-to-change-without-notice opinion. And the Dean is an absolute beast of effortless playability, so that one has pretty much supplanted all other guitars for the moment. I keep meaning to write a seven string shootout kind of review between these different axes, not that all but a few here would really give a sh*.