[unfixed]

I use a Glove 80 and I don't think I'll ever change keyboard model.

I think the combo of ortholinear, concave shape and multiple buttons for the thumb skyrocket my comfort level. Also, splitted to keep my hands at shoulder width is something I really appreciate.

But I guess that the key feature (that many keyboards share) is the ability to create multiple layouts. A dedicated numpad withouth moving the hand, a symbols layer, improve a lot the typing experience. I go with classic QWERTY with some minor tweaks, and is good enough.