As someone with long arms (5'9), I've always had trouble with long sleeves actually being long enough, and when you already can't sleep for whatever reason, cold wrists do not help. And while I was excited by the thumbholes, I was worried that the sleeves would be too short.
Luckily, this sleep top is absolutely perfect. The sleeves and body length on the medium are perfect, and the cowl neck is loose but still warm. Even though the colors I really wanted were sold out, I'm happy with the one I ended up with - the walnut melange is a warm grey.
It's incredibly thin, but so incredibly warm and responsive. I put it on immediately, even though it was cold from sitting outside, and it warmed up unbelievably quickly.
Definitely worth the money. I know I'm going to use it for a long time, and if I ever need another, I know where I'm going.