I finished those last week.
This first one is the one I made quickest: 3 hours, yet I think its still the most accurate. I don’t know why my images turn out better the less time I have. Must improve my detailing.
For this one I had much more time (8 hours roughly, in 3 sessions).
I’m also really happy how the next turned out. Great model – that makes a big difference. Also it was done in 2 sessions, yet since the pose and light changed so much, I nearly overpainted everything from the first session. And I think that was a blessing – again the shorter time helped to make the picture much less stiff.