Sudden thought: who in the OTU normally uses it - because neither the marine nor the army careers have realistic access to the Vacc Suit skill, which you need to wear the stuff effectively.
Now, I know some people will argue that the Marines' default Battle Dress/0 can be substituted, but whilst there's definitely some cross-over between the two, letting someone substitute level zero skills for one another seems to be pushing it.
Besides which, I can't see imperial marines using combat armour that much - since Uncle Strephon's boys tend to reach for battle dress for heavy infantry units, you'd think it'd be either cloth/light armour or battle dress without much between the two.
Now, I know some people will argue that the Marines' default Battle Dress/0 can be substituted, but whilst there's definitely some cross-over between the two, letting someone substitute level zero skills for one another seems to be pushing it.
Besides which, I can't see imperial marines using combat armour that much - since Uncle Strephon's boys tend to reach for battle dress for heavy infantry units, you'd think it'd be either cloth/light armour or battle dress without much between the two.