I would highly recommend TC on several heroic mode fights, and I'd appreciate you not appointing yourself some sort of final arbiter as regards Shaman talents. Our mana regen falls behind other healers', often by a very noticeable margin (indeed, that very blog notes as much with a more recent breakdown of regen among healers on his H-Rag kill), and TC acts to remove that discrepancy. I would argue that it would be ill advised to give up the opportunity to gain such an incredibly massive amount of regen on fights like Heroic Majordomo, Heroic Ragnaros (I even run with Unleashed Lightning for this fight, and the mana returns from being able to regen while dropping off seeds/dancing through World in Flames are almost obscene), Heroic Beth'tilac, and - albeit to a lesser extent now that the boss has been nerfed so hard - Heroic Baleroc.