A:AnswerI own both versions and the 4k downloads at lightning speeds and is also able to stream 4k movies. As long as you own a 4k television it'll be worth upgrading to the 4k stick.
A:AnswerYes I have a couple of old TVs that are not smart TVs and this allow me to stream.
Agreed cable companies are taking lots of money. However depending on which services you want to stream you still have to pay fees (examples are Netflix 13 usd, hbo 12 usd etcccc) si before you send the cable guys their way do a good research on your specific needs for tv watching.
Prices are estimations you need to do your research