What is the length of this jacket compared to the alpinist(XL)? What are differences

Mark, I would say that the Troll Wall has a lot more than just "decent" room for layering. In my opinion, it's a very ample cut; Excellent shell, but this is primarily a backcounty skiing shell; the snow skirt convinced me of that. It's really an all-mountain garment. Yes, the Alpinist is heavier, denser outer fabric, but it is more of a climbing shell. I have a TNF 900 fill Ultimate jacket (the one with actual serial numbers) and I can wear the Troll Wall over it. That's impressive.

Mark, I would say that the Troll Wall has a lot more than just "decent" room for layering. In my opinion, it's a very ample cut; Excellent shell, but this is primarily a backcounty skiing shell; the snow skirt convinced me of that. It's really an all-mountain garment. Yes, the Alpinist is heavier, denser outer fabric, but it is more of a climbing shell. I have a TNF 900 fill Ultimate jacket (the one with actual serial numbers) and I can wear the Troll Wall over it. That's impressive.

The Alpinist is a much longer jacket with more room to layer. Troll Wall has a shorter cut (would probably work for climbing), a slimmer fit but still has decent room for layering. I have the Troll Wall and think it is a fantastic jacket.

My understanding is that they're basically the same cut, except that the Troll Wall is a lighter (120 denier, if memory serves me correctly) nylon, when the Alpinist is a 240 denier I think.I got this from Marmot this past weekend because I called them with the exact same question. The guy I spoke to there was extremely knowledgeable -- give them a call. I have bought an Alpinist from S&C & was wondering about other possible options....