For the Testbed Bass I bought Labella Flats and Labella RX SS rounds, so can do lots of pickup string combo comparisions.
I put the RX SS rounds on my five string and really like them. They are supposed to be ‘bright’, but that B string had other plans for them. I didn’t really get bright out of the upper strings, just liked what I heard.
The other rounds I have on 2 basses are the MJC Ironworks rounds. I am leaning towards swapping them out with the RX SS strings as well, but not yet, need more time with them.