Sarah,
Well, probably...
BBC is available but the Science channel, not sure which one that is, Science Discovery or???
The verdict is still out on the Vizio setup but it only applies to the Vizio TVs I believe. I'm finding there are others like
G-Box Midnight MX2 Android 4.2 and I've just put that on my "Wish List" as I'm not convinced the Vizio is going to work correctly. Vizio has been sort of "Iffy" with quirks at times and doesn't seem to be corrected. (2 TVs, 35 and 45")
Best way of testing to see what you want that is to go onto your computer, go to the particular website you want and view the "Online Streaming". If it's what you want then that's what you'll get only on the TV. BBC is all over the place as are others, CNN, MSN, Fox etc.. and 'Al Jazeera America'.. CNBC etc.
If you also use local channels go to their websites and see if they have them there and try it out on your computer. Usually it's under "Live Streaming" or something along that line.
Just a heads up. With HD they do come in clear, but there are some glitches in a slight Stuttering and stalls at times but if you try it on your tablets or Computer, that's how it will probably look on the TV (not 'Tow Vehicle' this time, I keep thinking TV-TV when I see that acronym heheh not Tow V...)
I have to wait for the Streaming files to be loaded, frustrating at PBS as they have it broken down by segments at first, like 3min for this topic, 4min for that one and they eventually load in the Full Version. It's annoying at times but you just reset the viewing times. (good news is that they keep the files up so you can review older ones if missed)
Example:
PBS Newshour - I normally watched at 6pm right after the BBC America at 5:30. Can't watch it until 7pm or so if they get it posted then. Usually it's about 3-4 hrs later. You also have to move around to the website, you can ADD Fav and bookmarks that makes it easier.
As I mentioned, I use the news more than anything and if you don't watch TV programs, live series nor movies, then think of the "TV Box Player", as they are called, as a big web browser. It has to have the Browser available, most do not.
The key is that they do have Access to a browser and can access the internet. Without that, like Roku, you can only use the different apps provided, can't go to the 'outside' world.
Bottom line, if I wasn't concerned about $$ I would stay with the Cable. But??? I'm now saving apx $70mo which is 2 night's in La-la Campsite... so working it out...
Hope That Helps (HTH)
Sigh, On to the next one... heheh