Heavies are ridiculously heavily armed and armored infantrymen of every army. Wearing thick armor to protect them in their slow, terrible walks of destruction and wielding only the largest weapons they can carry, these titans of destruction can carve a path straight through lines of regular minifigs, destroy tanks like they were made of glass, or bust large holes in the sides of buildings.
Attracts Attention (-1): Wearing a hundred pounds of armor causes you to attract more attention to a 14-year old girl wearing a Sailor Moon costume to Comic-Con. All enemies get +1 on 'To Hit' rolls against the Heavy.
MORE DAKKA! (+1 cp): Heavies can carry up to 3" of equipment due to their insatiable desire to have more gun then your average NRA museum. This also means that heavies will flat-out refuse to use a one-handed weapon unless used in the off-hand of a 2-handed one. They can carry two hand-and-a-half weapons without a problem.
How does this sound? I'm thinking it needs to be nerfed a bit more. It probably costs more than it seems like, because you will want to buy a 3-inch gun, bomb, or melee weapon to go with it.