FWIW I've been tinkering with strings in various materials--skinny and not--for around 20 years.
Skinny strings certainly aren't anything new--Mr. Dan Quillian was advocating them when 450+ was still 450 Premium, and original FF was still the standard for "high performance" strings--back in the late 80's, I think?.
With the way every improvement that's been made to materials since B-35 seems to add another 10 or so fps to the shot, we should have traditional bows breaking the 300 fps mark by now! (insert sarcasm smile here)
Somehow though, a hickory selfbow with a 14-16 strand dacron string shooting 10 gpp will still shoot 165+ fps even with a fairly lousy release, and 200 fps with 10 gpp is still the "holy grail" with even the most modern recurves and longbows touting carbon lams, foam cores, and super-sonic strings.
I've made well over ten thousand strings (quit counting several years ago) and been involved with two sucessful string making videos, besides talking to lots of string makers, accomplished tournament shooters and hunters, several of the folks at BCY, and tons of regular folks like myself. I feel comfortable saying I've put my fair share of time in with strings. I'm not an expert by any stretch, but I'm not a beginner either.
I've seen lots of claims made by some fairly well-known folks (not string makers), ranging from flemish strings are "dangerous" to a string causing a bow limb to twist to giant performance differences just between flemish and endless. Makes me a bit of a skeptic I reckon, because I know none of these hold water.
Anyhow...the point remains the same. The answer to the question is a definate "maybe" as far as getting a big difference in results from different strings--performance or otherwise. What I've seen over the years is primarily a Ford/Chevy/Dodge type of argument--which one is best depends on who you ask.
I've been tinkering with the new 8190 lately. 12 strands makes a tiny string--really tiny--about the same size as 6 strands of Dynaflight '97. It's quiet, at least on my longbow--almost quiet enough to hunt with without any silencers...but it's not a lot different in that respect than every other string I've tried on it...8125, 450+, Dynaflight '97 in various strand counts. It's the strongest 100% Dyneema material on the market--very durable, very low stretch/creep--but again, not a huge difference vs. 8125, Dynaflight '97, 450+, etc.
The biggest difference I've noticed is when switching from dacron to a HMPE ("fast flight") type material--usually the hand shock is greatly reduced (I can't deal with hand shock). Other than that...not so much.
Easiest thing to do is try different things and see what you like. Lots of folks don't mind spending a ton of money trading/collecting different bows...spend a fraction of that tinkering with a string here and there...you might just be surprised at what you learn.
Chad