For me, strings are an impossibly black art, having played long enough to try most everything out there.
After the first several hours . . . . they all sound the same to me. Having lived thru the 'gee, that big B sure feels loose to me', I've never been really hung up about the way strings felt.
I agree with DF in that GHS offers just about any guage imaginable. In the old four-string days, I thought I wanted bigger G's and D's, and would custom guage a 50-65-85-105 set in Boomers that I liked (I played a LOT harder in those days before I discovered you could just turn the amp up . . . . ). Interestingly, it didn't seem to follow me to a five string set, didn't seem to work there. Maybe my hands and ears had changed by then. . . . at least it was nice to get past that stage where I was breaking E's and D's, framming them to death with Fender 355 heavy picks . . . .
So I do what I've always done: Go for a few years trying all the new / cool strings (only to realize I spent a lot of money and nothing changed), then invairably go back to Boomers or D'Ad Xl's.
Never tried flats (I'm old enough to remember when all basses SOUNDED like they had flatwounds and you'd see old geezes with those maroon tapewounds!), as roundwounds would sound like flatwounds for me pretty quickly. I did try GHS Brite Flats once . . . . I figured the 'Brite' must have meant how shiny they looked . . . .
Plus in my old age, I've gotten too grumpy to re-intonate and re-adjust the action for different string sets every time.
I am Living Proof of the Ancient Maxim: Take great care of your strings . . . . and they'll go dead anyway. It's just one more of those things that in my hormones-blazing, hair-on-fire youth kept me up nights: These days, I just don't think about it much.
J o e y