Tanks currently use Grade 7 Tinctures of Strength (Strength also affects tank magic potency, including healing).
The choice of opener is encounter-specific and depends on factors such as when downtime happens, melee disengages and choice of strat, kill-times, etc. See the Encounter Optimization page (Coming Soon!) for encounter-specific optimization.
In-depth Opener and Rotation Graphics
Slow GCD Rotation (new with 6.2, for 2.46 and slower GCD)
Fast GCD Rotation (legacy, for 2.45 and faster GCD)