High, I know this post is a tad late but I just recently joined this forum and like to post this for anyone in the market for this jacket. Just got the Montbell Alpine Light Down Parka and would like to comment on sizing (the review doesnt cover that at all).
I got this jacket is size Large (USA), the tag inside the jacket is marked as such (also says Europe Large and Japan XL). The jacket is cut VERY short. I measured a Center Back length of only 26 inches!! That is as long (or short) as some othe Mfg's SMALL sized jacket (or women's size). Even the Mountain Hardwear Phantom jacket, which is considered somewhat short measures around 27.5-28" in medium. I measured three jackets I have in large, 2 from Marmot and one from First Ascent and they all measured 28.5-29in center back length. What is weird is that the sleve length is correct (similar to the other jackets I have) and the chest is also close in size to other jackets. So If you are a stocky 5'-10" or less it might be ok.
That aside. The Monbell ALDP is awesome if it fits you. It packs down very small and has a TON of loft for the weight. The construction and materials are high quality. Its a warm jacket, much warmer than a patagonia down sweater and alpine ascents downlight sweater (both of which are thin). This montbell jacket has much more loft and a nice hood. I would definately keep it if it was 2-3in longer. Its a really good value for the money no question.

