Celestial Fists + Robe of the Whistling Fists

[TheBlob]

I have seen many epic monks with a Robe of the Whistling Fists and, from my understanding (never completed the monk epic), the robe isn't given back during epic and one would need to go through the trouble of doing the quest again to have an additional robe.

Is there a significant advantage to having the robe in addition to the epic? The haste shouldn't stack and the robe gives less HP than the Skyshrine chest piece. Is it for the STR buff (even if the haste doesn't stack, does the robe buff stick even with the epic buff)?

Or is it only a fashion choice or quest flex (and god knows I am all for fashion/quest flexes)?