Yes. I got my dad's old LG B8 (2018 model iirc) when he bought a newer model and it still looks great to this day.
One thing to remember is that TVs in stores are likely using some kind of vivid color preset, which isn't color accurate (some people do like oversaturated colors, I personally don't). The perfect contrast, though, is as impressive home as it is in the store.
I have a 2016 LG LED, and it doesn't have any ads either. I wouldn't say it's slow although that's subjective, some apps behave better than others though.
Based on the other comments it feels more like a Samsung problem more than a smart problem.