That list is based on BiS gear and hardmode raid buffs. If you're just in 5-toon heroics the DPS variation doesn't really matter much.
What I will add is that Unholy has a slower threat/damage ramp up curve than Frost (either variety). This means that you're slower to generate damage with Unholy which can mean overall lower total damage output in the fast kills of heroics. On the other hand, Frost is very bursty which means a higher total damage output for shorter fights but that comes with a lot of up-front threat. So you need to be slightly more cautious in the first few seconds of engagement as Frost compared to Unholy.
Also remember that DPS is just a quotient. Total damage out is what you should be looking at for boss fights.
[h5]"I'm gonna need to see more math I don't understand to believe all this"
"I'm not directly saying that you're this type of person, but I am implying it." -- Pigtails of DOOM!
Therion the Light of Dawn - Phezz the Insane - Snaffu @ Proudmoore US[/h5]