Yeah, It takes me two to three days to finish a full-detail page and I believe that's how long most of the creators finish a page.
But in my current series, I can finish 3 pages in one day(I draw about 7 hours/day) since the details are not much. ^O^
If you're a slow drawer(even though you draw for how many years), you can just adjust you art style according to your speed. But its not easy to adjust though. Quality or somethin' may drop.