I've been painting interior doors lately, takes about 30-45 minutes to do a coat on two doors that's cleanup and everything. I've been putting 3 coats with foam rollers, need to do baseboards and door trim but really not looking forward to that. Sanding old patchy paint in some areas and wood puddy imperfections.
Just using the cheap 6 panel hollow core doors. A nicer door without all the panels would paint faster.