I fell in love with EB Colbalt Flats on my jazz bass. Playing with the tone knob and plucking locations gives me all sorts of versatile tones. My RB-V has gone from GHS pressure wounds to Ken Smith Compressors (pressurewound style, I think). I prefer the Compressors to the GHS equivalent. Minor differences to my ears. I put pressurewounds on my 51-reissue and am in bass heaven with that instrument.
I'm currently trying EB Cobalt Flats on my single coil P-bass as well. I think your point about twiddling the tone knob and plucking locations is true - you can get everything from deep thud to growl and clank very quickly with them. These strings are the perfect answer for anybody who wants the best of both worlds.