Geth engineer with shield restore + geth infiltrator spec'd for melee = broken beyond believe.
And hunter mode is great, I think I spec'd my engineer as 6/5/3.

Also the boldier is waaaay more fun than the normal soldiers, I think they are boring too (well the krogan is kinda fun, cause it's a krogan).
Ditch blade armour abilitly all together and just go 6/0/6 with the boldier and he's a blast to play with.

Also the Justicar is either a godlike team player (geth shield engineer + defensive Justicar is godlike), or a close range wrecking ball. Though for the close range build I prefer the a-adept instead.