I prefer an open draw with a shank measurement at around 4.0-4.5 mm. In my experience the pipe will smoke cool and dry and they don't produce a pipe that gurgles. I have a screw in stem in a Meer and it is a piece of shit. It is an SMS which is not supposed to be a bad meer. I bought it before I knew anything about shank dimensions and screw on stems. Luckily it wasn't that long before I learned what I enjoy smoking.