They can take me anywhere between 30 min to a little over 1 hr. just depending upon how much detail I feel like putting in or is required. The small corrections and fine details like color and shading are what take the most amount of time which I do in the zoomed in mode.
This one took me a really long time. I think I went a little overboard on trying to get it to look right. Definitely probably the last time I'll spend this long on one.