I know it's an old topic, but I thought I'd mention gut strings...just put a set on my Boucher...oh man, it's like a pleasant homecoming. Nylgut is fine, but I like the tensioning of the gut (seems less than the nylgut). Slightly smaller diameters, and not so "slick" that your fingers glide right right across-it's easier to control "glide" passages with a slightly tackier feel, and less tension. Gives a tubbier, deeper, and rounded tone. I find many difficult passages are easier to play with gut. I had the nylgut on for over a year.
I've never really had a humidity problem with gut strings, unless it was an outright downpour. Guess I'll keep 'em for a while.
I'll just echo what everybody else is saying. I haven't used anything but gut strings since I took up the lower pitched minstrel music and technique, played on appropriate instruments, sometime around 1994. I keep them out of water, and they don't last forever, but gut strings are very durable and I find the feel and tone are clearly superior to nylon.
I get my gut strings from Bob Flesher. They're a bit pricey, but I like the gauges he provides. I made the mistake of getting gut strings from LaBella, thinking it would be a bargain. Well, you get what you pay for. The LaBella strings were way too flimsy for minstrel playing, or even playing tuned up to modern pitch. I also bought a set from George Wunderlich at a festival once, and they were good, though I don't know if George still sells strings. Good luck.
Thanks, Rob! I appreciate the help.