It's not just the extra, it's any warranty, Currys have the worst service going. Two TVs and two tablets at Currys both have been a nightmare, waited the full 28 days both times, one of which the TV actually sat in the shop for a month behind the counter, not only that nearly every time they tried to fob me off for another few weeks waiting while they "attempted a repair". For the tablet after two "repairs" I ended up claiming a refund off my credit cards warranty after their repair place wrote it off after only 48 hours. John Lewis on the other hand I've never had a single issue with warranty service, and they don't try and con you into overpriced extras, just tell you what you need and to get it on amazon.

You get that anyway. It's just that John Lewis make it easier to access.

http://www.which.co.uk/consumer-rights/regulation/sale-of-goods-act

I have a UE49KU6500 (49") which is basically the curved version of the KU6400 series & standard def sky looks really bad frankly. The good thing is, this TV has a built in Freeview HD & Freesat HD tuner. So you can get lots of HD channels through Freeview HD, you'll need an aerial for this like these: goo. gl/vjb2jP). Using the satellite cable that goes into your Sky box, you can also get pretty much all Sky channels using the built in satellite tuner, but the paid channels won't work as an actual Sky box is needed to decrypt those channels.