I have no real gripes about it, I just don't see the real benefit to me, but I'm a laptop user who always has my laptop in front of me. I can understand though how you like the ability to use your android phone to launch videos wirelessly. I love to use my phone to launch youtube videos on my PS3.
It just seems like so long as you already have an HDMI out connection (and a laptop infront of you at all times) it's more universal to just dual monitor. for instance while casting "Watch ESPN" on my PC to TV, I can't fullscreen the video in the tab so that the video on my TV is fullscreen and still use the PC.. which kind of defeats the purpose. but with dual monitor I can have the video fullscreened on my TV while still using my laptop screen for everything else.
If it were a wireless option to dual monitor I would LOVE IT! but that's not what it was intended to be. I like it being wireless, but since I already have a 15' ethernet cable (just prefer it to wifi when available), usb to mini usb cable to charge my ps3 controller, and a wired headset for my ps3, one extra cable (the hdmi) running across the floor doesn't really bother me too much.
It's cool tech and very affordable for what it is, but it just left me wanting much more... thought I had to be missing the point.
For people without a ps3 or xbox or multiple TV's/chromecasts I can see the advantage.. just not for me I suppose.
I mostly wanted it so that I could watch my comcast xfinity online account (watch espn/2/u, FX, FXX, etc to stream live TV as an alternative to my netflix while I'm away from home and have a real screen. the ps3 doesn't have an xfinity app and I liked the idea of being able to stream only 1 specific tab. but then I have to use the zoom function on the tv to make it fullscreen and still use the laptop.