The answer is always “it depends”. I love the Atreus for putting it in its carrying case and throwing it in my backpack. Then I can use my fun portable workstation setup on the go.
Even though I’m proficient on the Atreus, I can code faster on the Model 100. Numbers and symbols come out faster for me. So when I’m at my home base, I use the Model 100 in the “tent” configuration on my desk.
I also really enjoy making my Model 100 flat, and keeping it in my lap for casual typing in a comfortable chair. The Atreus would be too small for that to work well for me.
It takes my brain about a minute to switch modes from Atreus to Model 100 or vice-versa. I don’t mind this, but I can understand how some people would.