That's what i'm looking for!
I have bought so many flats from you in search of the right tension, what I should be asking you about is flexibility!
While I have enjoyed the hunt my wallet (and my wife) have not.
I'm looking into lighter guages, as my hands are killing me!
I play a Med scale Ibanez ABG, and a miKro, and love tapewounds but with the ABG the open E and all of the D string just does'nt cut it.
I know flats are it for me, but if all else fails I will have to go back to more flexible rounds.
What flats have you tried?
I don't have much experience with acoustic bass guitar (is yours 32" scale?), and I've only ever noodled on a Mikro (just under 30" scale, right?) once but, at the risk of repeating an olde refraine, if your hands are killing you, maybe you should check the setup of your instruments and your technique.
I've considered trying TI flats on a fretless fiver that I have. Never tried the TI B string, but I have a set of TIs on a fretted, four-string Brubaker Brute and they are wonderful on that bass (34" scale). They feel flexible but not floppy -- easy on the hands, provided one plays with a relatively efficient technique and relatively light touch. I've tried them on another bass, on which they did feel floppy. I think that if your bass is fairly solid, they'll be okay.
I liked the GHS flats on the aforementioned Ibanez 6 string, and I really dig the DR flats on a fretless, 5 string Carvin Icon (not sure I'd call them balanced, but they don't feel too far out of whack), but they both feel like a little more work for the left hand than the balanced tension Circle K rounds I usually use, whereas the TIs feel at least as easy (both the Circle Ks and the TIs are flexible, and the TIs are a little lighter in tension).
LaBella tapes feel easy-on-the-hands to me, too, but you've said tapes aren't what you're looking for (though, if the E and A feel funny, I'd want to make sure that everything's in order at the nut and bridge contact points).