Yeah, I've played with this set a lot in 4th gen. Its pretty solid in 5th.
Here are my notes:
Psychic probably does not deserve an Oo mention primarily because it leaves you extremely vulnerable to Tyranitar, whi will just screw you with Pursuit. Focus Blast hits Terrakion as well as rocking Ttar and doing a decent amount of damage to Scizor.
Terrakion + Magnezone make fantastic partners for this set. The former demolishes special walls that annoy gengar, while the latter shit stomps on Scizor / Ferrothorn who begin to eat you up once realizing that you are choiced.