I like a nice open and free draw. The closest thing I think you can relate it to would be sipping soda from a straw. If it feels like drinking a milkshake through a straw, then you are packed way too tight and will have burn issues and flavor issues working through the bowl.
A lot of the pipe's draw hole can make packing a pipe even more challenging. Especially if you are into older pipes, they seemed to use smaller draw holes back then. I am so obsessed with open draws that I re-drill any of my pipes that won't pass a 5/32 drill bit...