The minimal research I've done on Hisense is that they're not bad TVs by any means. TCL is likely your other best option around that quality/price range.
I'd say from personal experience, avoid Vizio, despite how attractive the price point might be.
OLED is great, but it's not for everybody. It really depends on your room. I'm incredibly happy with my OLED, but I may need to rotate it into a bedroom soon, because the living room at my soon to be new place might let a little too much light in for it to shine.
Either way, getting a protection plan on it is a must. Unfortunately, where a lot of the mid tier brands widen the gap in cost is components. It's a bit more common to see input failures, dead pixels, and other general mechanical fukkery with them.