I put a set of light-gauge Flex Steels on my Tobias about 18 months ago and loved what it did for the bass. Really brought out the best of the instrument. The strings have "deadened" somewhat, but I actually like where it's going. Normally, I like my strings fresh and change them out when they start to go, but I'm going to leave these on as long as possible. I'm a little worried that maybe I got a "magic" set that's just holding up really well, and that I'll be disappointed if I change them out.
I've tried the Flex Steels on all my other basses, with mixed results. I do have a set on my Suhr Jazz bass, but they're not quite "right" for that bass, and I'll probably change them out for nickel strings, probably Sunbeams in a lighter gauge. At the moment, they're still super bright and showing no signs of toning down.