In reply to Rog Wilko:
OK, a number of observations and thoughts here:
4k (aka Ultra High Definition aka UHD) is only likely to be detectably better than HD to the human eye if you have a significantly bigger screen than your current HD TV, or you are content to watch a similar-sized TV from significantly closer. If, like me, you are a person of a certain age with gradually deteriorating eyesight then the value of 4k is even more debatable.
Assuming that you adopt one of the above options to make 4k actually worth having in the first place, you will also need 4k content. That comes at a premium price - and may not actually be native 4k anyway.
This web site has some useful guidance about 4k screen size vs viewing distance, and some of the other potential gotchas around 4k:
https://referencehometheater.com/2013/commentary/4k-calculator/
My feeling is that if you really want 4k content then you may be better off looking at streaming content like Netflix or Amazon Prime, rather than a wireless broadcast medium like satellite. Arguably the market is slowly but surely moving that way anyway - after all, even Sky runs a streaming service now (though AFAIK it doesn't offer 4k yet). I think the likelihood of getting 4k on Freeview is extremely low - there isn't enough bandwidth in the increasingly small number of UHF channels being left for Freeview to accommodate the data rates required for 4k.
Bear in mind that 4k TVs are well on the way to being no longer a premium product - pretty much all of the latest models of sitting room-sized TVs have it, because fewer and fewer companies are making screens in those sizes with smaller than 4k resolution. It's the same as happened with HD: early adopters paid a premium for the kit and struggled to find content, now every TV is HD and all the public service channels are available in HD even on Freeview. (A lot of those early adopters probably didn't even realise that they were watching upscaled SD content rather than native HD. Arguably upscalers have improved since then as well, so upscaling from HD to 4k - which is also "easier" because the pixel ratio is so much simpler - is likely to be even more acceptable.)
My inclination, if I really needed to replace my TV now, would be to buy a 4k TV simply because that's pretty much the norm now, but to hold off on 4k content unless and until it covers my areas of interest (ie
not football!) at a price that suits my wallet. I'd also agree with captain paranoia that the "smart" features of TVs tend to become obsolete over time (and are often proprietary anyway), whereas a decent standalone streaming box (Roku/Fire TV stick/Chromecast/AppleTV? I don't really know the market that well) should get firmware updates to keep up with what's available in the general market.
Regarding your Freesat from Sky box: depending on how old it is that box may not even be HD capable. The fact that your satellite feed goes "through" the DVD recorder/player would suggest that there's a strong possibility that you've
never had HD into your TV even if the Freesat from Sky box
was HD capable. Especially so if the input to your TV is via SCART rather than HDMI. Bear in mind that DVD
isn't HD, so even if your DVD player
was outputting an HD signal (which it likely wouldn't be if you're using SCART) then it would be upscaled, not native HD.
Bottom line might actually be: do you really need to upgrade your TV? 4k may not give you what you think it will - especially so if you're not actually watching native HD currently. If your current TV
is actually HD (how old is it?) then you could replace your Sky box with a Freesat box (
not "from Sky" - you can buy Freesat branded HD satellite boxes from Argos, Currys, Amazon etc etc) that would give you HD broadcast content, and maybe a streaming box to access online HD content. If your current TV
isn't HD then by all means buy a new TV (though not necessarily a particularly "smart" one) and get 4k at little to no premium, but I'd suggest holding off spending money for 4k content until you've at least tried the interim step of HD.