Appreciate this write up. I loathe traveling with my Macbook Pro because it was so ridiculously expensive and I'm always worrying about it. A travel development laptop would be just what I'm interested in.
Not sure what type of development you're doing, but as mentioned above, this device works very well as a travel development laptop for my primary workloads (.NET/C# and Xcode/Swift).
Xcode performs surprisingly well, with relatively fast build times even on complex projects. Simulator performance is very good. I also tested PHP and Python workloads, results are more than acceptable.
However, Node.js, npm, and TypeScript/Angular development shows a more noticeable performance drop from M-level machines. Performance scales down with the number of project dependencies (is it related to SSD performance?).
Android Studio and Rider are usable for both editing and building, they occasionally become somewhat unresponsive, but nothing too frustrating. The one significant dark spot is the Android Emulator. It is very slow and unresponsive. Debugging with the emulator is almost unusable and feels like stepping back to the Android development experience of 2011.