It's a beast, that's for sure. I hesitate to give it too hearty an endorsement so early on, since neither it nor the company that makes it have any track record yet, but I have to say the initial signs are really good. It is massive, though, so be sure you don't mind that going in.
Well I dug deep and did some research on the OPO phone. The specs seem fairly nice! Beats the N5 specs (barely). The camera has a 13mp, and the one thing I fell in love with was the touch screen activation. When it is off, double tap screen for instant activation. Also, when the screen is off, you can draw figures on the screen to take you directly to that application (make a circle for camera, or a square for your flashlight). Being able to assign a figure that creates a shortcut while the phone is off, to say, the flashlight, is pretty huge for me, as I walk my dog late at night and would find this very advantageous.
However! This is the big drawback: the thing is all but impossible to get your hands on one! I joined the OPO forums and it seems the only real way (besides smashing your current phone and posting it to YouTube) is to get an invite from another person whom has one. And that forum reminds me of why I don't shop at specific grocery stores, I'm tired of all the people lining up and bombarding me with "can you spare any change?" As the forum is full of people begging for invites.
The OPO sports it's tag line of "don't settle" but it appears that unless you want to beg for spare change on that street corner asking for invites, we all may have to "settle". Hmmm. But I don't really see getting the N5 as settling. I just like the features of the OPO.