Yep the GX800 is another another goodie, especially for the extra 3 inches. These great value 2019 models won't be around forever unfortunately.
Try this Panasonic £629 5 Year Guarantee https://www.hughes.co.uk/product/tv-and-entertainment/televisions/all-televisions/panasonic/tx58gx800b?pdg=aud-664267144974:pla-901921619405:kwd-901921619405:cmp-222544245:adg-97099438261:crv-431556629429:pid-PAN-TX58GX800B:dev-m&gclid=EAIaIQobChMI1amVxqXt6QIVRLTtCh23QQDAEAUYASABEgJgJPD_BwE#show-hide--search (y) here some AV Experts! reviews https://www.expertreviews.co.uk/panasonic/1410904/panasonic-gx800-review and https://www.techradar.com/uk/reviews/panasonic-gx800-led-tv (y) if you're budget can stretch I recommend the Sony 55inch Xf900 was £677 recently (y)
Deal expired the AV Tv Expert says it (poo) ;( till my next deal (y)
For £600 @ 55" there are a few mid-range TV's that will offer good performance. Avoid this years models, as they are poorly priced at the moment, it's a great time to get a 2019 TV as the prices have come down a lot recently. Samsung's QE55Q60R is still available from a few retailers for around £600-£700. LG's 55SM8600 is £620 at Crampton and Moore. Hisense H55U8BUK is also priced similarly. All of these TV's have similar performance, and all of which are much better than the TV posted in this deal, which is newer, but lower end. You could save money by going down to the lower ranges though. Just be aware that in general, the panels get dimmer, and the colours more muted the lower down the ranges you go.
Dude there is no need to be so salty. Mute my comments in future if you can't deal with them. I'm here to help the buying public make an informed decision. Not to champion bad deals. You've already decided that I'm not an expert because I disagree with you. So It's pointless giving you an answer.