Who's running a catch can?

Nixlimited

No cons other than extra connections and a marginal amount of extra weight and space needed. Pros are less oil coating the intake tract as well as the fact that the vapor that is burnt off in the combustion chamber allegedly lowers your effective octane rating i.e. tends to promote detonation. That's what I was told at least on my old STI. I would be very surprised, however, if NA cars collected the same amount of oil as FI cars. The increased pressure of the FI tends to cause more blowby and more junk ending up in the intake tract. With that said, factory turbo cars come without catch cans so it may be overkill.

Note: I also had two lines on my STI and I ran twin cans rather than 1.