Shamelessly stealing from Crevan in this post on EJ:
Code:
2p_shoulders_head* 118943
2p_chest_head 118698
1p_head 118633
1p_shoulders 118619
2p_head_legs 118559
1p_legs 118528
2p_chest_shoulders 118493
4p+_off_legs 118492
2p_gloves_head 118478
2p_gloves_shoulders 118393
1p_gloves 118370
2p_shoulders_legs 118360
1p_chest 118291
2p_gloves_chest 118244
5p 118210
no tier 118114
2p_gloves_legs 118107
4p+_off_shoulders 117961
4p+off_gloves 117947
2p_chest_legs 117922
4p+off_head 117846
4p+off_chest 117634
So, take from that what you will. Keep in mind, Crevan ran this on a Patchwerk-style fight, which is where we would be more likely to see energy issues (due to not changing targets, and therefore not having any idle phases). It looks to me that 4P is very low on the list, but 2P did the best overall.
I think if you're ever encountering energy problems, 4P may be helpful for you. I personally don't find it as helpful (keeping in mind I am 494, with just barely 4K haste and 30% crit) with the change to Ascension, as there are times that it causes me to put off using my Fists of Fury. But I've found 2P to be helpful - less hurt if I make a mistake on FoF's usage, and the lower CD.
Also, you should run some numbers to see if maybe you can adjust how you use FoF. It's not always a DPS loss if you energy cap during it - I found that (provided I received all ticks) casting it at <89 energy was not a true DPS loss for me (keeping in mind the math is relatively new, so I may have run my numbers wrong and it may still have been a loss - it's hard to tell).