I have used Asus Zenfone 5 for around 7 months now.
Only problem I faced was battery draining quickly due to constant use.
Bough this one yesterday(21st Jan).
Using it for a a day now and have seen battery backup better than the original Zenfone 5.
The basic difference between this one and the original one is that they have different processor. This one comes with 1.2Ghz processor which actually helps for the cause. It consumes less battery due to under-clocking and certainly offers a decent backup now. Although its very early to say this but after using it for a day I have seen slow drainage while playing game and watching movies. Will update after 1 week of usage. Certainly its a very good buy. Just go for it.
Update after 4 days: - battery improving after charge cycle. New firmware available, updated it and getting extended battery backup now.
OTG is supported. can connect to wireless game-pads to play games too.
Wireless connection to other devices available via miracast. Will update more after few days of usage. Overall a very butter smooth performance.