While messing around in the GECK, I noticed that the game seems to use a particular list (NVTravelLightBadArmorList) to determine if a player is wearing "light armor" for the Travel Light, Light Touch, and Tunnel Runner perks. Seems like a bad design, but oh well.
One thing I've noticed is that "Combat armor, reinforced mark 2" seems to be missing from the list (http://fallout.wikia.com/wiki/Combat_armor,_reinforced_mark_2). Through console testing it looks like Tunnel Runner applies when you're wearing this armor, even though it's listed as "medium." Based on the GECK, it looks like the other perks should work, too. So there's a 25 DT armor set (incl. helm) that gets you the light-armor perks?
Anyone else noticed similar armors that act this way?