I don't use it in the RV, well haven't yet as I got it for Christmas this year and we will try it out in the camper this season.
Personally, we have a ROKU player and I think that has more options. In my opinion, the Chromecast just isn't there yet. There are alot of APPS coming out for it but, compared to what ROKU can do, you might want to look at that option. It's the same principle, just has more apps.
Chromecast you can stream youtube which is nice and you can also stream stuff from your Chrome browser on your laptop or phone. However, I noticed a good lag when doing so.
It works best for youtube and netflix through Chromecast.
With that being said, anything I use the ROKU for has been spot on.
With ROKU, there are channels available like History, PBS, A&E and others. However, when you access these channels it asks you to put a password in that your cable provider would have given you. If your cable provider is not on the list you can't really use that channel.
Major companies are on there but, some smaller ones just aren't available yet.
In the end, I'd recommend the ROKU but, again there are more things coming out daily for the Chromecast and Google does always seem to do things pretty well.