Fall 2017 I bought a mint low mile 2016 T3 174 SP. $8000. BRP Extended warranty. Felker clutching (supposedly a desirable thing). I'm 205 Lbs suited up w/avy pack plus about 20lbs of stuff strapped to sled (hijacker, 2 gal gas, linq bag). Carry shovel, folding saw, and Hijacker
https://high-jacker-snowmobile.myshopify.com. Best self rescue tool. Absolute must have, imho. Re getting stuck, this sled makes it easy to not get stuck.
I like that mine is the last year of the XM because I assume it is the best/most reliable version they could make. It has a full tunnel cooler (2015 have 1/2 cooler). Apparently there is a slight difference in front ends between 2015/2016 vs earlier years. I ride the rockies, off trail, at altitude. Love the traction and float. Re maneuverability, I think it allows me to go slower when navigating off trail through trees. The longer track does collect more snow. I have 2300(?) miles on it, still running strong. Ethanol free, Amsoil synthetic. Plan Trygstad 872 big bore when engine needs rebuild.
This year I'm upgrading the suspension. Bought x package take offs and had monster performance service, revalve, dual front springs. I plan to ride it for many years. I don't need the latest and greatest. This does everything I need it and does it well. Next upgrade is Alternative Impact a-arms. Most folks also do the Grip n Rip front brace. These are not the most robust front ends. I did a shocking amount of damage when I hit a rock under the snow at very very low speed. Front of ski kicked up, acted like a doorstop, lurched to a stop. E m module and s module, right spindles, a arms etc needed replacing. Took insurance check, did the work myself, used the leftover $ for lots of aftermarket upgrades.
If the 174 you're looking at has been well maintained but high miles you can get it for lower $, ride for a couple more years, then do the trygstad big bore.
Dootalk forum has tons of info. Members tend to be helpful and responsive.
You may be better off with a 163 or 154, due to your weight.