I can't speak to the quality but I'd imagine they're great. Most composers and arrangers I know use a pretty simple MIDI keyboard setup, or have become keyboard power users in their software and use a QWERTY keyboard.

Personally, I'm in group 2 (QWERTY keyboard) I have a digital piano at the workstation to test out voicings, but when I actually write I'm using keybindings on a QWERTY keyboard. Full disclosure - most of the writing I do is for schools, so I use notation software.