This is a fairly standard destro spec. Yours doesn't differ from it much, but here's why I think it would work out better for you:
Demonic power 2/2 Makes your imp do a bit more damage, but also increases the number of times you'll get the 100% critical hit buff from your imp (more imp attacks = more chances for imp to crit)
Suppression 3/3 would bring you much closer to the spell hit cap. If you know for certain you will be running with a spriest or boomkin giving +3% spell hit, you can trim suppression down to 1/3. If you have been raiding without someone providing +3% spell hit, that could account for a fair chunk of your DPS. Note though that with no misery/imp FF, you need to find another .5% hit or so to fully cap even with suppression 3/3.
Demonic Aegis 3/3 only provides a small boost to your spell power when you turn fel armor on, but it's still a boost.
There's some slack in the spec I linked, though. You can take out shadowfury (although I find it has some nice PvE utility) and you can optionally shift the 2 points in Demonic Embrace to Improved Healthstone if you like that utility more than the extra stamina.
I know you said your rotation is fine, but having 5/5 in improved corruption has me wondering if you are doing something different rotation-wise.
The standard spell rotation (that I am aware of) is:
CoE -or- CoD -> Immolate -> Conflagrate -> Chaos Bolt -> Incinerate X times (X depends on your haste)