REVIEW:
Google’s Daydream is basically a holster that makes use of a couple of lenses to convert the screen of a compatible cell phone into a virtual reality spectator. The Daydream item has no electronic gears by itself. The processing, as well as angle detection requirements, for VR are all managed by the phone itself.
Daydream’s out-of-the-box setup experience is definitely the simplest of any VR headset on the market. After installing the Daydream app on a compatible phone (currently, only Google Pixel qualifies), you just flip down the front of the headset, insert the mobile, close it up with the help of a bungee strap, press the goggles onto your face, and stiffen a single elastic band behind your skull. Apart from the download, it only takes less than a minute to enter the VR tutorial from a complete standing start.
Daydream will leave a few red “VR face” marks after extended use, but it won’t turn you a wet, sweaty mess like HTC’s Vive will. The VR image produced by the Pixel’s 1080p screen is astoundingly acceptable for a cell phone. However, there’s some “warping” around the edges when you incline your head around the 3D scene and you can certainly figure out individual pixels at the short distance, with a little of the “screen door” effect among those pixels. Though, none of that is distracting enough while gazing around at the abstract world in front of you.
A great part of the component’s usability is most probably due to app design that allows things to update smoothly as you tilt your head around. Basic in-game objects are rendered with sharp, spotless lines, but the head-tracking doesn’t comprise of positional tracking, so leaning forward or shifting around feels weird as the complete VR world comes along for the ride.
What makes Daydream stand out from many alike mobile-phone-meets-VR-holsters that have originated before is the additionally included handheld controller. The miniature, rounded disc feels much like a tiny version of the Wii Remote, comprehensive with an accelerometer that can sense tilt and basic motion in your hand. The Daydream controller also encompasses a small, touch-sensitive area under the thumb, which may be used to flick through selections.
Google Daydream has its own exclusive platform and store to deliver compatible apps. The store is pretty uncomplicated to navigate either in VR mode or on the phone itself, and it offers a comparatively compromising experience for discovering and purchasing games and apps.
PROS:
Convenient and simple setup
Relatively light headset
Responsive and sharp visuals for phone-based VR
Controller provides a simple and instinctive VR interface
CONS:
A rather restricted field of view
Phone might get hot after rapid VR sessions
Limited software and app support at the moment.
Light interference from outside can produce a reasonable glare on optics.
More here:
http://simianvr.com/gear/google-daydream-review/ 
