If you're going OLED it's best to buy LG, because you have the ability to repair it practically anywhere in the US.
When it comes down to LCD, you should get the Samsung 4k 7000 series or higher. That's cost effective at $1500 for 50 - 55 inch range.
AND.... Samsung's 4K screens do give you a really NICE advantage with 1080 pictures. The color. Their 4k panels have the ability to sense colors better than the old 1080 panels did. You can get 3 different shades of purple on a 4k TV compared to 1 shade of purple on a 1080 TV. The moment I saw that... I was sold on 4K and Samsung.
And I am impressed with LG's Panels too.
I used to love Sony, thought they were the best. But then they got in bed with Sharp. The quality isn't there anymore. Don't care for the fact you need to download software from the service website each and every time I have to install a Sony or Sharp main board. That gets old fast.
Do yourself a favor.
Buy Samsung, or buy LG. As for that other TV stuttering...it probably needed to have it's MOTION control settings turned OFF. People doodle around with it in stores, used to be they'd just shift the tint and color. Now it's motion control and inputs.
If you have questions I'll be home this evening.