When I dictate, I write about 5000 per hour, but when I factor in the editing time it goes down to maybe 3000 an hour and is the least interesting editing work I’ve ever done, so I don’t use it for anything except writing sprints any more.
Now I do writing sprints every morning with a few writing friends, and usually get 2000 an hour when things are going great, and 1000 an hour when the words just don’t want to come. This is the best balance for me where if I have to toss or rework a scene I don’t feel frustrated at all the lost progress, but my alpha readers don’t get too distracted by a technically poor first draft. My schedule is writing from 8 AM to 10 AM or so, in five-minute bursts and check-ins with the others every fifteen minutes. I really need to become more productive, actually.
As for length, the advice I trust the most at the moment is to consider 70K words your minimum, because that’s the point Audible readers believe a credit is worth their money, but aside from that your genre will determine your ideal length so you should look at examples from your genre which are well-received, you like a lot, and were published within the last couple years at most.
"...the one with whom he so sought to talk has already interceded for him." -The Master and Margarita