I've never thought much about string materials until recently.
I've owned a handful of bows and have always bought new strings for them when I picked them up as a bloke down this way (Jack Spinks) makes a great string and he's a top bloke as well.
Besides one 652 string currently on my heavy Widow, all the others have been D97. No complaints, ever.
Every now and then I shoot bows belonging to other people at club shoots and some of them have a really off feel/sound to them. I never understood why and assumed that it was just because they were lower poundage bows, presumably shooting very heavy arrows. The ASL's have been the weirdest/worst. A big SPRONG kind of sound. felt different in the hand. I figured I just wasn't used to other bows.
Fastforward to a week or so ago and I got my new SPL Pacific Styk in the mail. I strung it up and had a few shots and the feel was fantastic but there was a slight feeling of that weirdness I described earlier. The string seemed to be more 'rubber band-ish', if that makes sense? I took a D97 string off my other longbow and strung up my new one and had some shots and it immediately felt better to me.
I could have put some silencers on the B55 string and been perfectly happy, no worries, but I was genuinely surprised at the difference that just the string made.
The B55 string is on my bowfishing rig now. I can't see any reason for me to not use D97 in the future for most things.
Interesting discussion in this thread.