MIDI keyboard versus computer keyboard input

I think it's personal preference. Personally, I find computer keyboard at least as efficient, and hugely more practical, than MIDI. Others do find MIDI easier to deal with especially if they don't do so well with note names or aren't comfortable with notating rhythm (although the latter is not going to be an issue when transcribing, only when composing in real time).

But Step-time MIDI input is not going to have much chance of being faster since it is literally the same number of actions to press a key on the MIDI keyboard as on a computer keyboard, and where computer entry requires correction of octave, MIDI keyboard requires correction of enharmonic spelling, so it's about a wash. It's going to come down to which way you personally can "think" faster, and for me it's the same either way.

Real-time MIDI input is still pretty limited in MuseScore, and even in programs that had more robust real-time input, I never found it to be more efficient personally - too fussy to get things notated correctly. And I'm a professional pianist, so it's not a question of me not playing accurately enough - it's just the nature of the amount of guesswork required. I've used various different notation programs for the past 25 years. The only one in which I ever found MIDI input to be close to as efficient as computer keyboard was Notator for the old Atari ST, and that is because it was a sequencer first and notation program second.