I think these are good points:
LBR
I prefer flemish because they are quieter...
Rob DiStefano
IMHO, I prefer endless 'cause they're just easier/way faster to spin (than mess with twisting), and an endless string can be easily made to very precise loop-to-loop lengths that will not change much at all since there are very very few twists to stretch out.
Because they seen quieter, I've been twisting Flemish strings...
zilla
I have been making Flemish strings for quite a while. I have noticed that repeatability of length can be an issue once in a while.
...and have settled upon a techinque for ending up with a certain number of twists-per-inch in my finished, shot-in strings.
O.L. Adcock
Strings are stronger with twists, you won't find cables or ropes that aren't twisted for that reason. An untwisted/unwaxed string will "flair/parachute" during the shot which is bad news.
Differences between strings performance wise is caused by mass and aerodynamics. Stretch/springiness has nothing to do with it. A string is as stretched/sprung as it's ever going to be at brace height. The tension on the string is about 30% less at full draw as it is at brace.
The point in OL's second paragraph is an excellent one.
But I'm still wondering: how many twists per inch in a Flemish string? The responses seem to range from "1 in 2 inches" (Falk) to "2 to 3 per inch" (a material vendor's web site.)
I've decided that the number of twists used to form the plaits under the crotch depends on the material being used and the weight of the bow. I used to start my taper (I pull out one strand per twist) as few as three twists below the crotch. FastFlight is slicker and seems to need more and heavy bows seem to need more -- otherwise the strings seem to start to start stretching again after 500 shots or so and I'm guessing that they're pulling apart in the plaits. (Extra strands for padding come into play, too: more strands mean more twists to complete tapered plaits.)
I don't think 1/2 per inch is going to get it for a FastFlight string on an 80# bow. But are 2 per inch too many? Hmm....