Here's my take on them. After playing DA XLs heavies on my EMG P/J equipped BB3000 for many years, I switched last winter to TI Jazz rounds (thanks Mike D!). I really liked the TI acoustic set on my Ren fretless and loved the low tension (after I got used to it). From what I could find out about the Jazz rounds, they would fit the music I play and give me the lower tension I was looking for.
Mostly, I need a somewhat old school sound, with the ability to get some cut when I want it. They've been pretty much perfect for me. Slightly thicker in the mids (my D and G strings sound fuller) than the XLs, they are smoother to the touch and to the ear. After a few hours break in, they don't have the somewhat edgy treble sound that I would have to dial out with the XLs. They are touch sensitive so when I dig in, they cut with a nice mid honk. I've had them on my bass for about 6 months (approximately 40-60 hours a month) and I'm just starting to feel like I need a new set. YMMV.
Here's a bite from a gig when they were about 3 months old. P 90%/ J 60%/ treble 70%. SWR220/Fishman Pro EQ DI.
File is about 525K, Zydeco T live at Jake's: Invalid Link Removed