I use this String on a Jazz Archtop Guitar.
I've tried a lot of string, flat, semiflat, round but never found the ringht one.
When I've put this strings on my guitar I feel like in heaven, the sound is perfect for jazz, smooth but not so dark...you can play other genres with satisfaction.
The really cool thing of this strings is that tension is very well balanced, every strings has the same tensione, instead of other strings wich has the 3rd string that is very higher tension.
I can't tell you only a bad thing about this strings, they sound great and tension is fantastic...the price is not so cheap but it's definetly worth buying it!