Semper_fi,
What toggles are you using and how often are they on? Before ED and the Stamina 6 slotted I never had a problem with End on my 32 Inv/EM Tank. I ran with all my toggles on at all times (silly) and never worried. I was mostly diversified in my slots before.
Now, Stamina is 3 slotted I'm still diversified and my end is mostly gone with a 3 person mob. My tank is level 36 and I run with Manuevers, TI, UNY and In at all times w a End Red in each. It looks like I'll need to add more End reducers to my toggles to help some of the endurance bleeding.
Perse