So basically there is no fight where NV > HoTW for this tier as far as dps is concerned? Even Jin'rokh that is as close as it gets to having uptime = to nv's cooldown it's less than a 100% modifier so HoTW > NV apparently.
I should say I used NV on Lei Shen and for one of the bouncing ball collapses I successfully used NV as a healing cooldown while aoeing them. It might not be as good as hotw tranq or even rejuving the raid if extra healing is needed during its duration (or if you don't need to use it for the raid, as a personal healing cooldown) but you are also doing damage while you heal which means in the case of lei shen that the adds are going down faster as well as heals coming to the raid. It was enough to keep us up with regular healing and no other cooldowns whereas for the other ones we were mostly using dedicated cooldowns for each (honestly tho I can't remember now if it was one of the ones where we stayed stacked up before they came out, so maybe it's not as useful as I think :P). Maybe it's not necessary now that it should be on farm but for learning it was useful.
I generally do more healing with NV over HotW throughout a whole fight but I haven't really checked how much of that is overhealing. It may not be as clutch as a HotW tranq but it can still give your healers a break should they need to use a potion or whatever. I do think this talent has it's place in contributing to healing but if your math is right then it appears from a pure dps perspective and possibly having a strong single point healing cooldown that HotW is superior in most instances. I guess I just wanted to point out a place where I found NV useful, even if for this weeks lei shen kill I plan to use HotW