Both the Head and the tail can be unscrewed. I believe the A1 A2 and C1 share Head and Program . C2 is based on Wizard.
There is a edge where the head meets body. I can see it catching some dust, lint etc etc.
The button is stiff. It took some getting use to for sure. I use my thumb.
I have the CW and I ordered the Warm today. I will get a C2w as soon as Going Gear has them.
Just got my A1 warm today. The cool white is going to Market Place.....