Its simple enough but reliability is a huge issue for me. Since I got the Apple TV I havent had any drop outs and disconnects like I do with Chromecast. With Chromecast I can expect 1-2 dropouts for every 15 minutes of streaming. I commend google on chromecast only for the price but the apps, reliability and support for it sucks.
To be fair, I know little about the Chromecast and it's reliability. AppleTV works great but if you don't have another Apple devise its only mediocre. I much prefer the Roku for standalone.