Setup was a little difficult at first, but most things are difficult when you swap two digits in your password. When you first load the device up, it will tell you to go to a URL. I went there on my Galaxy S3, and was greeted with an app link. Once I downloaded the app, it discovered a device was on the network I was on. How did it do this? I'm not actually sure. It didn't know any of the networks authentication at this point, so I'm guessing there's something low level with mac addresses that allows that to work.
After clicking on the device, it puts a code on the TV and one on your device just to make sure you're talking to the right device. It will then ask you what network you want to connect to, and it's credentials. After entering those, you're all set up to go. It was actually fairly easy.
My favorite part of setup was that the android app switched my wifi network from my home wifi to the chromecast acting as an access point for setup until it itself could connect to the home network.
Operating the device could hardly be more intuitive. Clicking the icon on any supported app allows you to transfer the content to that device. I watched a few netflix shows, and it worked well. My only complaint, which is probably more or less unavoidable, is that there is a good lag between doing something like changing volume, or pressing pause and the chromecast actually responding to your request.
Something else that I disliked was how content wouldn't always save its position. If I want to pause a youtube video, switch to streaming a tab, and then go back to the youtube video, the video had to start over. Obviously that's just an issue with the youtube app not saving the position.
How It Works
Currently, development is very limited. They are in the beta stages of development, and you can't develop for a device unless it's been whitelisted. I'm still waiting on my device to be whitelisted for development.
One security concern I have is that any device on the network can access your chromecast if they want to. I would love it if the chromecast had a password to be able to access it, but would then whitelist those devices' mac address or some uuid for the device. Either way, I'd like it to be a little more secure on public networks.
Overall, I like the device. Should you go out right now and buy one? Probably. I feel like this technology should be worth more than $35, and the price might go up once people get their hands on the official SDK.