By "cast," you mean "tell the Chromecast to fetch/display content", rather than "show streaming video of my device's screen"?
This is part of what I'm asking: I don't get the usage model. I prefer using the STB directly with a remote (and no other client device), or pushing the client device's screen to the STB. If you're saying that you use "tabcasting" (which I guess is remotely-directed Chromecast web surfing), then fine. It's not something I'd ever use, but I understand that the equivalent doesn't exist on other STBs.
Please don't get me wrong: I would prefer if there were an open AirPlay equivalent that Android and iOS devices supported at the OS level. But I don't think that's what you're talking about.
The idea is that your phone (or tablet or laptop or whatever) becomes your remote. If you want to watch something on Netflix you pull the phone out of your pocket, launch your Netflix app, and then hit the Chromecast button to send the output to the TV. It's not a separate UI, just a separate destination for the video content you've already selected. For me, the simple fact of never having to hunt for a remote is enough to justify the $35.
On a technical level: what the chromecast is doing is simply streaming content from local devices on the Wifi LAN. It has no UI of its own and won't fetch content by itself. The codec suite is limited when compared to Android: it supports H.264 baseline, VP8, MP3 and AAC. And I believe the container must be either MP4 or WebM.
No, you can also stream to the chromecast. e.g. Google's "cast tab". I use it to watch stuff off my plex server or hulu (don't have a hulu plus account).
This is part of what I'm asking: I don't get the usage model. I prefer using the STB directly with a remote (and no other client device), or pushing the client device's screen to the STB. If you're saying that you use "tabcasting" (which I guess is remotely-directed Chromecast web surfing), then fine. It's not something I'd ever use, but I understand that the equivalent doesn't exist on other STBs.
Please don't get me wrong: I would prefer if there were an open AirPlay equivalent that Android and iOS devices supported at the OS level. But I don't think that's what you're talking about.