I don't know anything about those. I own/have owned the E17, O2, CMOY, and C&C BH, and I have heard the E11. Most equipment gets a lot of hype on the web and on Head-Fi. Lot of people swearing how great their amp is, only they don't really have experience with other amps (so of course it sounds great to them).
Whereas I trust ClieOS's rankings. He reviews DAPs, amps, and IEMs
, and everything I've bought that he's reviewed has been spot on. If you look at his full review for amps, he's even measuring them. For example, FiiO E12
(google his username with the make model to find longer reviews). So his reviews are way more informed than even CNET's audio equipment reviews, and even though he is self-publishing, he's essentially a professional reviewer of high caliber.
So my suggestion is pick from his rankings/reviews unless you can order a couple of amps and test subjectively test them against each other to see which sound better to you. The odds of you picking something different from what his rankings at a price point and having it be better are slim to none. More likely, you would end up picking worse. Does that make sense?