No need for speculation, the law is very simple and clear as is demonstrated in the article. The Sale Of Goods Act trumps any EULA or any contract that you may or may not sign with whatever small print may be buried in it. I know, I've been there and done that and got the refund. The general rule of thumb for an electronic device is that it must be working with all its *original* features for about 6 years (not always that long, but nearly always - its estimated on "expected" lifetime) or you are entitled to your money back. The word "original" is important. You can add new features, but you can't take away features that were present at the point of sale. It's as simple as that. Ignore what any shop assistants/managers say, they will always try to wriggle their way out of it. Especially ignore what the manufacturer says as it is not them who you will be dealing with. You don't even need a receipt - the manufacturer can verify which retailer a given serial number was sold from.
On top of that, the EU directive on consumer protection allows the retailer the same rights as the consumer upwards in the chain. Sony WILL pay out when the retailers come calling or they will find themselves in a court case that they will definitely lose.
Thank $deity for a decent set of consumer protection laws this side of the pond.