I received my third Pipe601 today and its the first cartridge drinker. Upon closer inspection and comaprison with Pipe601 one and two I made the discovery that Pipe three is missing a shot of glue exposing a hole behind the copper/brass pillar. Seems the added air intake from the missing glue provides more air pressure to aid in wicking out liquid from the cartridge. This added air intake also adds air thus knocks down the throathit from the vapor. This is especially true since I've been dripping for two weeks and have developed a preference for the direct-drip atomization.