Disclaimer: got it cheap.
-heavier than advertised— reg mummy claimed at 425g when I bought it, Nemo updated their site to say 445g recently, and I measured it at 470g (not including pump sack, stuff sack, etc)
-40d/20d nylon is now essentially equivalent to the Xlite, so hopefully the durability issues are resolved
-3.5” height is less of an issue than I expected wrt cramped tents— the baffle design works really well at partial inflation, so you can get a nice ergonomic curve without bottoming out. My heels hang off the edge of 72” long old school self inflating thermarests, but I get a bit of a hammock effect with the Nemo without bottoming out, so it’s effectively longer. Baffle design is fantastic.
-somewhat annoying valve placement— since it’s not at the edge, it’s challenging to get the last bit of air out.
-I’m a little peeved the pump sack doesn’t have a wider opening, it would be nice if it doubled as a drybag.
-I can‘t personally judge the limits of warmth yet (8.5R), but I don’t think anyone has complained that the xtherm isn’t warm enough.
-not a fan of the black colored top— warmer colors go a long way when stuck in a tent waiting out a storm.
-noise level is crinkling paper, not chip bags