sorry, sent too early. Hate mobile. Anyway, yeah pretty good response. However what you said about how Tenacity is pretty much only useful if it saves a Healer CD.
No. Not at all. Hard disagree. Taking less damage is always useful, especially if you get by a TB and are left with miniscule fractions of your health left. Tenacity is literally a life-saver in said situation.

Also, Determination affects the actual potency of a healing spell (Clemency).