I play a variety of Jazz styles (Jazz standards, Bossa Nova, Be Bop, Jazz Blues).
I was pleasantly surprised and very impressed with the Galli flat wounds. After trying many flat wound brands for my '59 Byrdland, the 13-52 and 14-56 sets provide the best overall versatility for a variety of jazz tones.
What works on my L-5 (Thomastic Swing and Be Bop sets work great), fell short on the Byrdland, which requires heavier gauges with the shorter 23.5" scale. Both Guitars have carved spruce tops, but Byrdland has 1 1/4" less body depth.
Galli strings on the Byrdland & 1965 BF Deluxe Reverb combo, retain the same depth as pure nickel flat wounds, but are livelier (but not bright).
A multitude of tones (from Grant Green-Wes- Benson, etc) can be had by varying the pick shape, thickness, material, etc.
* D'Addario Chromes were lively but rather sterile.
* Pyramid pure Nickel Flats were a close second to Gallis, full, round, but less lively and a little darker. These are great if you want a Grant Green or Jim Hall tone.
* La Bella Jazz Flats- Dead out of the box.. made the Byrdland sound like a bass guitar.
* Thomastic Swing were rather dead sounding and bass heavy on low E & A.
* Thomastic Be Bops were too bright for versatile Jazz tones.