It does the following:
- Additional shield capacity.
- Additional air control.
- Additional laser damage.
- Randomly shocks nearby enemies when damaged.
- Randomly heals you.
- Randomly restores your shields. (This in particular seems to proc A LOT, and usually just when you need it.)
- Randomly drops health vials and ammo (and really small amounts of money) when you get kills.
Outside ultra-specialized builds (melee builds built around a Maylay Shield where you don’t want your shields restored, for instance), why would you use anything else? It just does so many different things, both on offense and especially on defense, that it clearly outclasses any other Oz Kit, IMHO, and probably is the most powerful item in the game overall.