Just from looking at the skill tree, however, it seems more beneficial to drop as many implants into Walker as possible as it unlocks nearly double the amount of skills in addition to giving you access to a wider range of weaponry. These upgrades are performed at special stations located around the ship, and have the bonus functionality of letting you upgrade your own and Harvey's statistics as well as whatever weaponry you're carrying around.
Doing most of this requires parts. It seems as though GPG is going for a streamlined sort of design with Space Siege, since these parts are pretty much the entirety to what enemies give out when defeated. They're not littering the ground with weaponry, armor, cash and various items or upgrades, just parts, which are added to a single total. And when you do get weapons, which happens very rarely according the producer we were talking to, you keep every one in a sort of permanent inventory, meaning you don't have to ditch or sell unused weaponry.
It's an interesting contrast to the droves of action-RPGs out there that seem to hinge on the "drop as much flashy crap as possible" formula and we look forward to seeing how it works once we get a build of the game in the office.