Got both the XL Auto and Manual... For me, the auto is my go-to, the manual is my secondary. Got both about a month ago.
I duunno if its changed but the manual has a 5 sec cuttoff. You can negate this by releasing the button at about the 4 second mark then pressing it again, but its kind of annoying.
The biggest difference though is the air-flow. The manual has a much harder draw (too hard if you ask me) than the auto which is the main reason why I like the auto better (where I find the draw to be just right). Because of this (for me at least) I seem to get more vapor, in less time, with less stress on the diaphragm with the auto.
This also means that the auto requires less cleaning than the manual, because those holes can get clogged up pretty quickly.
Hope this helps!!!