Looks like prices of the 1070's will drop (well, continue to drop) in the not too distant future and if I were to find one at around £220 or less would it be worth swapping it in for a 1060? Rig is hooked up to a 4K TV but only running an i3 (Haswell) but I figure with the high resolution the CPU isn't much of a bottleneck.
Over a Haswell? The only way to upgrade his CPU enough to be justifiable over a GPU upgrade, would be to also upgrade his mobo/platform. Still, why are you trying to run a 4k panel off an i3/1060 system anyways? Even if you got £120-150 for your 1060, spending an extra £100 for a 1070 is really down to your expectations on performance - it was never meant to be a 4K GPU, but if the games you're playing need that extra 20-25% to move into the "playable" realm and you can afford it, then why not?
If you want to play at 4k, then your looking at 1080ti realistically, unless you want to compromise on visuals. I don't think the upgrade from a 1060 to a 1070 isn't worth the hassle or money for the meager performance increase IMHO.
Which is why I am saying that he'd be better off getting a quad CPU. The 4670Ks are decently priced nowadays.
I should add that the games I'm playing (DiRT and GRID mainly) actually run alright at 4K without the settings turned down too far. This isn't a case of getting it to work, just improving what I've got and for it to last a bit longer. I thought the jump from a 1060 to 1070 was more like 40% but if it's really just 20-25% then maybe it isn't worth the money to upgrade new.
It feels like the cost relative to the performance boost isn't particularly attractive, imho, but as @Wakka says, if that boost gets you the extra performance that you need then why not go for it? Based on current prices, though, I'd go for a 1660Ti rather than a 1070 (unless there are some crazy 1070 deals out there that I've missed). I also wouldn't count on 1070 prices continuing to drop away - typically, as inventory dries up the prices of older EOL tech go up, not down.
Read a few reports that there is quite a lot of stock that needs shifting from both Nvidia and AMD. I've already seen a 1070 for £250 from Zotac.
At the expense of looking like garbage, though? Haven't seen 1 example of DLSS doing anything less than ahniliating image quality - I would expect an FPS boost for that!
Nah the patched out versions (post garbage) look fine dude. Have a look on OC3D, Mark (Wyp) retested Metro Exodus.