Is regrowth worth the mana in dungeons

[Snazzytoast02 0]

I always see Druids hate on regrowth because of its high mana cost and while it isn't worth it in a raid I think it is pretty good in dungeons, any opinions on this?

[Easy Waters 0]

Situational but I fit it in. Mainly when I feel the heal output is higher then incoming dmg. Or if like a few adds are on someone I'll use regrowth 

[Storfan 24]

Situational. Definitely usable, but dont use it as your main healing spell, for that you should be using HT.

[Duality 4]

Situational. 
In terms of mana efficiency regrowth is fairly viable IF the initial heal doesn't overheal and IF you allow the HoT to tick efficiently, meaning that you keep the tank at roughly 90% so that the HoT isn't wasted as overhealing. If you have a HoT running on your tank, you can also allow yourself to downrank Healing Touch one rank further to save a bit of mana that way, OR you can take advantage of the 5 sec rule. If the tank dmg should spike unexpectedly it is also nice to have a HoT active to use Swiftmend. 

[metagame 8]

If it lets you get a 5-second rule mana regen tick it might be slightly better than using your most efficient healing touch rank.