Re: Best Flatwound strings?
I believe the Pyramids and Thomastik's are the only flats with pure nickel wrap, most of the others use stainless steel, that makes a big difference in tone. The Pryamids are expensive, but Pyramid strings give the old 50'-60's sound, not as bright as the modern stainless steel wrapped strings. And the tone lasts a long time, so you have to consider that in the price. They are not dull sounding, the 12-string sets are great for the early Beatles 12-string sound, and have some snap to them. I love Pyramid strings, can't always afford them (I have around 7 electric guitars), but when I can get some on sale I grab some. I like the Pyramid Classic pure nickel-wound round-wounds, I think they are the best round-core pure nickel string around, they cost twice as much as most other strings but it is worth it, IMO. But those are round-wounds. The flats are equally awesome.
Also, doesn't Rotosound make a Monel-wrap flat wound string?. Monel is a nickel composition, and might be a good compromise. Never used them myself, and this is from memory and might be wrong, maybe you should check them out. I might be remembering the bass strings.
Al