btw, for anyone interested - you can get the lg up970 for £160 or less from Rainforest.
I got one from the warehouse for £130 (basically a returned unit with a small scratch on the side) when the price was still £200. Typical it was a build prior to Aug 17 which are infamous for 4k disks causing a huge vibration at the start and end of movies. I mean, this thing sounded like a lawnmower! Putting 4kg of weight on the top would stop it but that wasn't a very good solution
Popped it open and mounted the optical drive using those rubber washer/dampener things you get for mounting hard disks to cases. Also stuck some of that thick double sided tape on the top of the drive (leaving the top of the tape unpeeled) although no idea if that was needed. Now can just hear the hum of where the disc spins up to ludicrous speed at start and end. Can't be heard over tv and definitely not if in cabinet so happy enough with that. When not going ballistic it's silent. Also not a whisper for normal blu-ray and DVD.
How did this thing ever get past QA?! Anyway, by far cheapest way of watching 4k discs with dolby vision. Looks blooming good too (fair enough, I've got nothing to compare it to!).