Just bought a set of ecb81 xl strings from my local GC, and they sound great! Wide range of tones from the typical McCartney thump to the Geddy Lee or John Entwistle punch sound. Nice, smooth surface to slide without squeaking. 

 They perform just as well as this ad states.

They're my flatwounds of choice on my Precisions, I love em.
Bass Gear:

Mensinger: Speesy
Fender Precision 1989 (CIJ Rosewood)
Fender Steve Harris (CIJ)
Lakland J Sonic 5
Epiphone Explorer
Maruszczyk (custom) Jake

Ashdown CTM 100