I would like to hear how people are using this new pitch before duration function. I don’t find myself using it, because it’s an update. If someone could share how they use it, I would love to incorporate it into my workflow as well! Thanks.
For me, I have my midi keyboard underneath the top of my desk, on a large pullout shelf - shifting my hands is not much different than moving a hand(s) to the mouse. The relevance to your question (I hope) is that I use pitch before duration to play freely and free my mind a bit from thinking of specifically of intervals and notes.
If all I wanted was a specific pitch, short phrase or chord, I’ll play each note and hit duration to capture it. But I switch back to the other mode for most writing. Or I’ll record. Just me though.
I should mention that its particularly useful for guitar, as I don’t have all the frets memorized in standard tuning, much less others. 
I have guitar midi software that I feed to the guitar staff, and its just very nice in pitch/duration mode.
I find it great for anyone that composes directly into Dorico. If I’m doing a straight copy job where I don’t have to think about the notes, then sure, duration-first is probably faster. When I’m writing directly into Dorico I want the freedom to play whatever I want on my MIDI keyboard, and then when I’ve figured out the line, voicing, whatever, quickly input it, all without leaving the input cursor. Before pitch-first input came along, I would have to exit and then restart input a gazillion times in every project which was a huge waste of time, and that’s not even counting the times I would forget the input cursor was or wasn’t active. Pitch-first is a huge time saver, and my compositional workflow isn’t being constantly interrupted as I can just leave the input cursor active.
That all sounds great! I usually do that step on cubase, but I’ll give it a go on Dorico. Sounds like Dorico is getting more intuitive now. Hope it continues that way and somehow merge into cubase in the near future!