My recommendation is LG based on my scarce experience with TVs.
I purchases Hisense 4K only to return it. A serious flaw in picture became noticeable ONLY at certain movie scene. I watched same movie on other TV set as well as on computer to ensure movie stream was fine, and it indeed was the Hisense TV's fault. Picture colors had an issue more prominent in certain pre-set color settings than the others, but ALL presets had color problem. Software on Hiense was Roku & was also poor comparatively. The only good thing in Hisense's Roku software was that you can hear audio wirelessly on multiple mobile phones with Roku app installed. Unlike FireTV's bluetooth where ONLY 1 bluetooth can be connected.
I ended up buying FireTV 4K. Picture quality is best BUT software is annoying at certain things. Most annoying is a serious lag after pressing btn & menu response.
e.g. in my 7 yr old LG, I can change color presets with 1-2 button clicks. while on FireTV I have to go through 5-7 clicks to achieve the same.
FireTV's remote eats up batteries like a hungry "کَٹَّا". While 7 yr old LG's remote needed battery change once in 6 months or even longer, this FireTV needs battery change every month.
Most recent Prime update also degraded the Prime's experience and regretfully I cannot revert back to old version.
7 yr old LG if 720p -vs- 4K FireTV but LG still has pretty good picture quality for a 720p.
FireTV sets are made by some other companies. e.g. at one time they were made by a japanese company , but then FireTV's were made by Chinese TLC. Hence on my FireTV, the back panel of FireTV is EXACTLY same as that of TLC. It could possibly be some other manufacturer now.
Picture on FireTV are very good, but remote, battery consumption, & software lag are a nag.