Is the Gyroscopic Harness weapon accessory missing some important notes?
As written, you're paying 1,000 CBills for nothing but +1 Recoil Compensation and the privilege of becoming Encumbered.
There's a brief mention in the Machine Guns section about using them with Autocannons, but that's about it.
I'm guessing that the missing information is probably the paragraph or two from the old Lostech book that reduces the crew requirements for Support Weapons that are labelled as "semi-portable".
