What about advertising
The other month Amazon decided to send me an e-mail to promote Norton Antivirus despite the fact that I've been opted out of promotional e-mails with Amazon for years. When I questioned this they said it was because I'd spent over £30 with my last order. Since then, I've not purchased anything from Amazon that exceeds £29.99 and its' surprising what bargains you can find elsewhere. For example, I purchased a new TV in August from John Lewis for the same price as Amazon but with a free five year guarantee. Fair enough, I had to pay the postage but still, it's a far better deal.
My point being... I loath companies that think they have a God given right to promote their products and services to me and this is why I wouldn't consider Amazon Fire TV. If they're not already advertising on the TV then it can't be far off. You're much better off waiting until a product is released by a UK data controller so that you can opt out of all direct marketing - even marketing served to a TV.