From my personal exp mages are harder then locks. Few weeks ago got my lock to 90 geared up and got to 2.2 in 150 games doing shadowcleave as afflic and i didn't play lock for at least 4 years. Then i tried mage and yes doing damage is easy but what's not is trying to survive while being trained at the same time trying to put some kind of pressure and cc. Yes occasionally ice lances kill targets but then it just lol games.
I saw Venruki fighting blood in WOD it was hilarious how good blood performed. After ven and his shadow killed other blood's partner blood went ahead and almost killed them both showing some awesome survival and damage.
Ven left the game