Not a fan at all of the "have guys cum into a bowl or bowls for 30-45 minutes and then have her struggle to swallow it" scenes. By then it's probably all watery, cold, etc. I much prefer more swallows, and quicker.
The scenes that turn me on the most are what I call "rapid swallow" scenes. Ichika Kuroki does some in her Idea Pocket 100 series (IPD 665) and Mika Osawa does some scenes like this too. There are a few out there but they are so few and far between. I know a lot of people enjoy watching a girl collect a lot in her mouth and/or play with it in her mouth for a while before swallowing, and I do too to a certain extent, but why not let the girl swallow it immediately more often? Let her taste it at it's freshest moment. We need more of these.