While Shield has no endurance management abilities outside of OWTS (30% +recovery for 120s), I find Willpower's endurance management to be lacking as well. WP gets 30% +recovery in Quick Recovery, plus 30% for 120s in SoW and 200% for 90s in Resurgence. The issue is that it has no end drain or -recovery resistance. Facing Arachnos Mu, Malta Sappers and similar foes, it's painfully easy to be end drained and toggle dropped. Shield actually fares better in this regard as its defense blocks many end draining attacks.
The armor sets with fulsome -end/-rec protection are Bio, Dark, Elec, Rad and Stone. These also include +end/+rec tools (Dark requires Obscure Sustenance).