After trying dozens of strings on my Flukes and Fleas...for each strings/instrument combo below - all very clear, very crisp, great note separation, good sustain...but each a slightly different sound...
- for now I have stayed on Martin M620 strings on my concert Flea in GCEA tuning...
- and on one tenor Flea, walnut top, birch rosette, wood fingerboard, the Aquila REDS in F-Bb-D-G tuning...(if I get a concert Flea with a wood fretboard later on, THESE are my favorite strings on this instrument)
- and the other tenor Flea, hibiscus red top, plastic fingerboard, Worth Browns (BT) in F-Bb-D-G tuning...
- and on the tenor Fluke, koa top, wood fingerboard, Martin M620, in E-A-C#-F# tuning...
and so far I am really liking the sound and feel this way.
Hope this helps.