I have this exact tv, got it a few months ago and I mostly use it for Netflix (4k goodness) and also run my gaming PC through it (980ti) for a 4k desktop, it works like a 4 x 25" x 1080p monitor setup, it's really good. I'd highly recommend it as a TV to use for inputs; PCs, Consoles etc. as the input lag is low in Gaming mode and it supports 4k 60Hz and 1080p 120Hz (good for FPS and general smooth gaming). However the smart functions are pretty poor (compared to competitors), the games and apps are akin to what comes on a knockoff iPhone and casting functions are limited, the speakers are quite good though and the panel is very good.

In short, to run a PC through or console or Amazon Fire box (4k one), YES.
As a standalone Smart TV for a living room, probably not, unless you only watch Youtube, iPlayer and Netflix. I'd recommend an Android TV instead.

P.S. No Youtube 4k on this TV

Well I got one I the end. Response time is ok. I'm still working out the picture settings. But it is an odd tv sometimes top notch...4k YouTube looked very nice via tv ...via play station it was stuttering maybe because of settings over all I'll give it an 8 but only because it's cheap. There's definitely a vignette and viewing angles are not great but I guess that's this type of screen for you...bit like one of my monitors. Definitely not as good as my old plasma in some ways but that cost twice as much. But as I say in some situations it's amazing. Not pumped any top rez 4k stuff out yet...manual is awful tells me nothing about specs. It does have hdcp 2.2 on two 2.0 hdmis apparently but only says hdmi 2 @ 60Hz in manual....Not tested this...

Do your research too... depends on your viewing distance.

Under the specifications section it has a cross next to HDR, where does it say that it's HDR.

I read on a forum someone saying that the box even says its HDR, one second..I will find the link for ya.

55 inch model but I assume the specs are the same.

That would make this TV roughly 50% cheaper than other HDR tvs, unless I'm wrong in assuming that HDR tvs are around 800 -900 for an entry level hdr TV ... sounds a bit too good to be true, hope it is though

This is a bargain kids

HDR from external sources only.

https://www.avforums.com/threads/hisense-55-65k720-owners-thread-ltdn-k720wtseu.1996033/page-142

If it has HDR then this is a bargain but I would still go for the 55 inch model because for 4K to be more noticeable you need a 55inch tv