As a tank Green Dragonblood is my best friend, so I keep it going all the time or use it as a lifesaver. Unfortunately I can't see my character while it is active, except for his beating heart hovering midair whereever I go. Without looking at my skillbar I can't identify which weaponset I currently use, especially when I use sword and board for both slots. Apart from that It's a bit annoying to not be some knight clad in armour holding up his shield but some jerk who seems to have botched an invisibility spell...
I really would love to see this skill with a completely different effect. One that does not completely cloak the character and shows off his/her heart. Some aura thing like on Grim Focus, Rapid Maneuver or even like the Templar's healing ultimate would be nice...