For what it's worth I'm 6' 165ish and 27 y/o, and went 186 K108.
Use them for almost entirely all-mountain and touring through a freestyle / jib lens, though they've been fun and solid on jump lines too. They're quite a bit of ski even at my size (compared to the noodles I've ridden in the past) and I'll admit they kicked my ass at first before I got used to em. After a season on them I could imagine enjoying the 191 in specific scenarios and still the 181 in others, but the 186 is perfect for what I wanted out of them.
Gonna be honest it's hard to imagine someone 3" shorter and 35lb lighter enjoying the same balance on this ski - If I were you I'd go 181 and not be worried about it at all.
Always worth a chat with the ON3P homies on the website if you're unconvinced though. Scott helped me through the exact same question for both times I got skis from them. Super helpful understanding tradeoffs related to size and whatnot.
