Have to admit, completely love our Smart TV. Replaced the previous 7 old telly, which has plenty of life in it, so gave it to the Mother in Law. The Smart functionality is a 1000 times better than the previous BT connected box, and although we're not big TV watchers, what we do watch tends to be streamed from catchup services like iPlayer, or watch a film from Amazon Prime (formerly Love Film) which costs £6 a month.
The kids love having You Tube on the telly, although if I have to watch the theme song from Frozen once more I'll have a breakdown.
There is a full browser on the TV, but unless you have a keyboard, I don't see the point. I was tempted to login to Facebook for a laugh, but after reading this, shall stay clear of logging in any online accounts, and certainly wouldn't do any online banking on the telly!
The only compromise I can think of would be my Amazon account, so I guess that's one to watch, but theres (currently) no widespread panic of Amazon Prime accounts getting hacked, and goods ordered fraudulently.