This is very comparable to an armada berk with stp +3 and DA +3. You lose 11 Dex, some accuracy, 2 stp but gain extra str and attack and 1 DA. Personally I would use this.
Wooo! They went all over the place for mats on this thing:
Pak Corselet/+1 - [LEATHERCRAFT - Expert, SMITHING - ???, GOLDSMITHING - ???] Earth Crystal, Adaman Sheet, Behemoth leather x2, Mercury, Siren's macrame, Fiendish skin, Scintillant ingot, Tanzanite jewel
Seems like an excellent body piece for setups requiring a minimum of STP+4 on your body piece (and holy *** DA+4%). Otherwise, for builds requiring STP+6, Hauberk will still reign king.
