First of all, it is not a miracle device. What Chromecast does is to cast "cast-supported" apps from your smart phones, tablets, and stream media from your laptops and PCs to the TV on the same local network (LAN).Setup is easy and straight-forward. Connect Chromecast to your TV, download Chromecast apps from Google Play / iTune to your device, making sure Wifi-is on, setup Chromecast's Wifi connection via your mobile device, and it is done. Setup only needs to be done once. Other supported devices connected to the same local network will then all be able to use the same Chromecast.Now Google Play has a section dedicated to Chromecast compatible apps. For some reason, this section is only shown via Google Play app, not browser version, but going to chromcast.com/apps would also give you the list. Currently the selection is quite limited, with a great deal of them just variations of apps for streaming media from your local computers and media servers to Chromecast. Others like YouTube, Netflix, Hulu, and so on frequently requires paid subscription to truly make a difference.Basically, Chromecast combines your mobile device and TV into a fast-response SmartTV.The Touch-Ups which could potentially make Chromecast a perfect device:Currently, the only way to cast PC Desktop screens onto Chromecasted TV is to download the Google Chrome extension "Google Cast" by Google (sorry, mobile Google Chrome is currently not supported). It gives your the option to stream a dedicated browser Tab or cast the entire desktop screen. However, there are some flaws:1. In general, casting would mess up your Google Chrome "non-maxed" window size. It is a mild annoyance, but still annoying anyhow.2. Tab cast mode has no option to display mouse cursor. Not an issue for portable laptops, but a serious issue for a casting PC from another room.3. Desktop cast mode does display mouse cursor, but it could only cast the whole desktop. If you have a multiple monitor setup, it practically makes the cast useless.4. Neither Tab mode nor Desktop mode have build-in PC control mechanism. Although this could be easily fixed by using app such as "Unified Remote," it is still one extra step.*How 4. works, Google Cast to cast PC desktop + Unified Remote on your tablet/smart phone to control the PC -> result displays on TV**Better solution: Chomecast app integrates with Google Cast. It still needs PC, TV, and mobile device to work, but require one less app to install.If the above touch-ups could be implemented, Google Chromecast could be a potentially monopoly-accused TV casting device. 

Question: How is the device?
Answer: it is not a miracle device