Isn't the dead ends ilvl synced anyways? Pretty sure it syncs to i570 at most. If you're above 570 then you're absolutely fine.
Besides that DRKs tend to be a bit high maintenance and you feel it if they aren't using their mitigation more than other tanks. Even if they do pop TBN as frequently as possible though, they tend to need more heals and attention, especially if your DPS slacks off. If the pull takes too long to clear then it will be very, very rough.