Yes, the higher up the quality ladder you go, the more likely the TV is to be a smart TV.* That’s the reason I got one–not because I particularly wanted a smart TV, but because nobody makes a dumb TV with the other features I wanted (in my case, the best possible picture quality.)
I have a Bluetooth keyboard I can use with my Smart TV, and while it connects, it isn’t always useful. The reason is that, unfortunately, each individual app has to be designed to accept keyboard input; it’s not enough that the TV has a keyboard connected. If the people who programmed the Samsung Smart TV Netflix app didn’t program in keyboard support, you’re stuck spelling words with an arrow control and an OK button.
*Is there a name for this phenomenon in the world of commerce, where different characteristics like size, build quality, and features tend to increase together, so that you can’t get one without the others? I’m encountering it also as my mother considers getting a new car–she wants something the size of her Honda Civic, but with leather power adjustable seats and xenon headlights and all kinds of luxury features that don’t tend to be available in small cars.
The reason your smart TV is so great is because the software was written by Roku. I may be slightly biased since I work for Roku, but I’ve also seen a lot of “smart” TVs, and I’ve never seen one that is remotely comparable to Roku TVs in terms of software quality and ease of use. Generally TV manufacturers are great at building hardware and terrible at writing software. A lot of manufacturers are coming to realize this themselves and are putting Roku software in their TVs, including Hisense, TCL, Insignia, Sharp, LG, Hitachi and Haier.
BTW, Hisense is not (yet) well known in the US, but it is the largest TV manufacturer in China and the third largest TV manufacturer in the world.