I have a friend who does this. His logic is that leaving the leaves on while drying exposes the buds to less light, resulting in better quality. I don't agree with this, since my drying plants get all of 10 seconds of light per day (when I open the closet to freshen up the air).
It would be nice to get some pictures here of perfectly trimmed bud... close ups and all. I'm struggling too on deciding how to trim
From what I've read in many articles and written experiences all over the net it's better to trim after drying. The slower the dry the smoother and more complex the smoke will be. I haven't had any first-hand experience myself but when it comes time (a few weeks from now) I'll be trying the slow-dry method. I've waited all this time growing the plant. What's a few days extra to dry? In the end, hopefully, I'll have a nice mellow, tasty smoke with each toke.