I have a Icon Pro l/xl. I find it just about too big. I’m 5’8”, 175. Wear a 34 pant that is too loose, 33 are just right. My pack belt has about 13” of extra belt on both sides. Meaning after I tighten the belt there is over 12” of belt flopping around on both sides.
I’d recommend the s/m, or just call Kuiu, they’ll set you straight.
If anyone wants to trade a small for a large, let me know.