I do like Eos for 8man, especially when paired with an AST or another SCH. Pre-52, aoe healing is a pain, and even post, it can be troublesome, so Whispering Dawn is pretty helpful. If swiftfast is up, I will swap to eos for dps checks or when the boss takes extra damage followed by a period of dodging mechanics (Ravana's Swift Liberation). I like using Eos for Chrysalis too because there's so much going on and people ignore mechanics, especially for the time freeze part, because i think it benefits from the extended buff duration, making it last the whole phase.