Well it all comes down to this:
Nugget:Good Defense And Attack.Helpful with Battles and Being the 2nd Defense/attack line.perfect for battles that will kill u easily.
Medkit:Medkit however is better for those who dont get involved that much and prefer to Stay at the Back And Kill.
Its Best Stats are in Attack and agility.
overall i would say nugget for its usefulness in battle.but then again and my buddy sonic said its mainly on ur playing style.