Originally Posted by
Nestar
by 80 it usually evens out, In full BiS twink gear on my 80 I'm doing 4-5x more dmg as shadow. Prior to the enchant scaling/nerf I was seeing 90-110k dps in a raid situation, Bursting as high as 250k. In disc with the same gear was more like 30-40k. Every single heal capped DA if it crit in that setup, That obviously decreases the value of mastery a bit. Crit build still seemed really strong for disc still though.
As far as shadow goes, As others have said, mastery is awesome at 80, Get whatever haste you can, preferably to the same breakpoints as you would aim for at 90 and then all out mastery. 25% should be easily attainable in that gear.