I have been using XBox 360 for streaming YouTube, Netflix, and occasionally Amazon Prime Videos.
Recently bought chromecast to enable casting and reducing wires and cables in my home, but my experience with casting wasn't as great as I expected it to be.
For starters, netflix casting from my android mobile isnot really as smoothe as Netflix app on XBox. While browsing, play/pause or forward/rewind, the casting loses its context and comes back to main screen, which is really annoying.
I watch streamed videos from my laptop on my TV using HDMI cable. I thought that casting such videos on TV without HDMI would save me some trouble setting up the cable etc, but the experience wasn't really nice. The videos, even though they stream fine on laptop, do not cast nicely on TV. There is a lot of jitter and lag, so much that I ended up using my HDMI cable again. note that I have a TWC's rented modem which is best in class, so wouldn't think that router or wireless network would be an issue.
Overall, I haven't really found a good use for this except sometimes casting photos from mobile to TV, or the entire mobile screen for that matter.