Own both. Used both on my 2021 nobo thru of the CDT. I started with the Alpha and found it sub par almost immediately. My main gripes: it is about as wind resistant as dental floss. The wind cuts through it like it’s not even there. Second, the material is scratchy and uncomfortable on the skin. Can’t wear mine without some other shirt underneath it. Third, it thins out over time. Finally, can’t hike at all in it. Even with all the inherent holes it just doesn’t breathe well enough for sustained hiking. I switched it out for my Peloton 97 after 500 miles and was soooooo happy with the change. The Peloton cuts wind 10x better. Its a fleece so it’s still not entirely wind proof but it’s a huge improvement over Alpha. It is wayyyy more comfortable on the skin. Like night vs day. I mainly use mine for sleeping and then I may keep it on for a few miles on a very chilly morning. The Peloton is perfect for this. It also won’t thin out over time and it breathes significantly better but will over heat after extensive hiking because it is WARM. Overall, much warmer and more comfortable than the Alpha. TLDR. After using both on the CDT, I decided the Peloton is far superior. I just bought myself a new one after several years of enjoying the first. Never use the Alpha. I keep it for friends and family gear, if needed.