The YotaPhone isn't yet ready to deliver on its dual-screen promise due to various issues ranging from poor build quality to short battery life and, most importantly, an inability to make use of its rear E Ink panel except in a very limited selection of pre-installed apps. Without support for our favorite e-book and magazine platforms, or for Spotify and other streaming apps, or transport updates and Google Now (which we're told is coming soon), there just isn't much reason for us to flip the phone over.
What's needed is a big push on the software front. Not just in terms of stimulating third-party app developers to take the YotaPhone seriously, but also by reducing the phone's reliance on those developers in the first place. This might happen through better mirroring of the LCD onto the E Ink side, rather than the stagnant screengrab-mirroring we have now, alongside some kind of mapping from swipe gestures to standard navigation functions (forwards, backwards, play, pause, et cetera).
This lack of support could potentially be solved within this generation of the product, through some major software updates, but we wouldn't rush out to buy the YotaPhone unless and until that happens. The other option is to wait for a complete hardware revision, in the hope that it'll bring a full touch-sensitive E Ink panel or some other solution. Either way, with all the expertise Yota Devices has gained in putting this type of display into a phone, there's a much better chance that this type of hybrid handset will one day be successful.