So I got these strings last week and I thought I'd review them. I am using them on a FSR MIM Fender Jazz bass. The string sizes are .45 .65 .85 .105. These are the first flatwounds I've ever tried. In the past, I've used the roundwounds that came on my bass, Ernie Ball Nickel Slinkys and Cobalts, DR stainless steel Lo Riders, Rotosound Swing Bass strings and Rotosound Solo Bass strings. The Rotosound Jazz Bass strings are higher tension than any of those strings. Playing anywhere between the neck and neck pickup feels a lot like playing between the 2 pickups with roundwounds of the same gauge. These strings were REALLY rough on my fingers, but now my fingers seem to have gotten used to them. Well, when I first put them on and started playing, I thought "Roundwounds!". They really don't/didn't sound like flatwounds. More like roundwounds with not as many overtones. They had a great finger/pick/slap tone, although they aren't THAT great for slap now that they've been on the bass for a while. It seems like the D and G strings have lost more zing than the A and E strings. It's not that bad though. The finger noise was quite low since they are flatwounds, and they've been getting less noisy the more I've been playing them. With both pickups on full, it's a great classic Fender J tone. The tone really shines when I solo the neck pickup. The midrange seems to ROAR. It's a great tone. They are nice and twangy with the bridge pickup soloed, and it seems like they sound less harsh than roundwounds with that pickup. I really like these strings, and I think these may wind up being my string of choice. They have an awesome sound in the midrange. They can get a really good flatwound-like sound with a mute and the tone knob rolled down. Almost exactly like John Paul Jones's sound on Led Zeppelin II. They can get a really good roundwound-like sound with the tone rolled all the way up, the treble boosted on the amp, and by digging into the strings. I would say they sound like a cross between roundwounds and flatwounds. These are possibly the most versatile strings I've ever used, and I wonder how they'll sound as they age!