Received this in Dec just before Xmas so the delivery aspect was excellent. The ordering process may be a bit complicated but I think the explanation and guide were easy to understand so had no problem there.
Built quality is fine I guess, not to my liking but still better than some others in the market.
I don't know if I need to do some burn-in or not but so far I must agree with the majority of all the others' reviewers on this one that say this is just an average headphone. I have the fostex by modhouse, aiva which all are great headphones with RRP roughly on par (+/- $30ish) and they all produce a much better quality that the poseidon. Lucky I got this on kickstarter price but definitely won't buy them at full price.
One good thing about it is that it is easy to drive so no need to get high spec stuff but if you only want easy to drive headphone then why would you get this one in the first place.
The only reason I'm still holding on to this is because I am yet to try this with tube amp since that what amazed Zeos.
So yeah, I'm still giving this another chance to prove itself.