Everyone is different, but personally I won’t buy a keyboard without separate Delete and Backspace keys, without Home/End/PgUp/PgDn/Insert keys, and without a dedicated Menu key [0], for any kind of serious work.
I’d also imagine that one is prone to bump into the rotary knob if one is not fully conditioned to that keyboard.
I applaud the T-shaped cursor block and the full-sized function keys, although it would be useful to color the function keys differently in groups of four (cf. the standard PC layout).
I’d also rather do without an Fn key, as it messes up muscle memory from regular desktop keyboards.
I like the idea of using different key shapes for the number row and the cursor keys for tactile recognition, although I’d have to try it to see if those shapes are any good for actual typing. I feel that slightly concave keycaps will always be the best.