The Hardplate series by Rubicon Industries is a set of heavy-duty armor. No other armor series provides anywhere near its level of physical (not to mention overall) protection. Its thermal and chemical defense just about match the Ronson "R" Series and Shotlite Dragonfly armor, respectively.
Unfortunately, all this defense comes at the price of a high movement penalty for each piece, and the Helm and Gauntlets also increase reload time. Unless this set is used by a Heavy with a good amount of points invested in the Heavy Gear skill, augmenting the Pants and Boots with Machine Assisted, and/or putting points into Fast Movement, is practically mandatory due to the armor's hefty movement penalties. Augmenting the Gauntlets with Nimble and/or getting some points into Fast Reload will help alleviate the reload penalties of the Helm and Gauntlets.
It is not advised to equip the entire Hardplate series to achieve 99% resistance in each damage category: Though this series has the highest physical defense and excellent thermal defense, it's outclassed by Dragonfly and Medusa armor in chemical defense. Thus, players going for 99% resistance to all damage types should equip some pieces of Medusa armor, or, if enough points have been invested in BAE, simply go with full Graphene.
If players need mobility with good defense, it is advisable to mix Hardplate pieces with ones from other series to balance the whole stat of their characters.
Example: Mixing Hardplate vest with some pieces from Shotlite will reduce some portions of the speed penalty from the vest.
If players either uses Heavy class or simply ofter plays Apocalypse and/or Last Man Standing, equipping a full set of Hardplate pieces will ensure their chances to survive the battles.
Example: A Heavy character with better Hold The Line and equips a full set of Hardplate parrs will become an immovable fortress, which provides extremely effective support for the whole team.
It's recommended to avoid using the entire of this set in Vaccine mission due to the time limit as well as final boss being tougher as the game progresses. One suggestion is to ignore the boss & sprint as fast as possible to the dropship once the vaccine is secured. Another is mixing its parts with other armor pieces to minimize the movement penalty as much as possible.