First some backround. I recently got my alt Shaman to 80 and was running some things with some guildies. One of the guildies is normally a resto Shammy, but she was enchance for farming over the weekend so instead of bringing my main, they asked me to bring by not very well geared resto shammy. Overall I and they felt I did very well, but there were some points that i went OOM. The other shammy brought it to my attention that I was not recasting Water Shield mid-fight when the Orbs were consumed by crits. Another guildie mentioned that it may not be worth it to take that talent as that is time wasted recasting the Water Shield, and that w/o taking the talent I could keep my mp5 up.
So that brings me to the question, which one is right? Is it better to take the tlent and recast Water Shield mid-fight, or just not take the talent and rely on mp5 to keep my mana pool up?