I used MT Prio in EQ2 because the requirements of having a well geared tank there were much higher than it seems to be in wow. Currently we only run 10 mans and myself and the Pally tank we have are quite able to look at each other and work out who gets more from a specific piece. If there is no clear winner in terms of who gets more from the upgrade, we /roll on it.
At least that's how we plan to do it once every fucking NAXX boss has had enough of the "lets drop 2 bits of leather" joke. HA fucking HA guys.