Actually, it's a myth that it
improves cooling, and I never said that
http://www.procooling.com/articles/h...g__-_phaes.php
The bottom line is that it doesn't improve cooling, that specs calls for negative pressure, but that regardless, proper ducting is what's really relevant. Otherwise a good read, especially about that Plextor fan.
Personally, I prefer to have positive pressure, but my priority is still proper ducting, as applicable.