IMO, I wouldn't get hung up on "skinny". Every controlled test I know of (Hooter Shooter and chronograph) showed very little if any performance gain, plus you loose stability, consistency, and durability...all the big benefits you get from these materials to begin with. I'm no Rod Jenkins, but I have tried them off and on for the past 20 years...can't find any real benefit. Black Widow had a challenge out a few years ago offering a free bow if someone could show a gain of...I think it was 4 fps with their string vs. BW's standard 14 strand Dynaflight '97. The "catch" was if your string didn't show that gain, you had to buy a bow at regular cost. To the best of my knowledge nobody even tried.
Material-wise, the quietest (before tuning) has always been blended materials...450+, BCY-X, and now X-99. They will also be the most stable in higher temperatures.
Course everyone has their preferances. YMMV