Yeh, when using sale of goods to try and get a problem fixed, warranties are just an obstacle when arguing with the company. They are completely irrelevant, as is whether the manufacturer will repair the item. It is the shop that should repair or replace.
I've tried the sale of goods thing twice, once with Halfords where I lost the will to live as it took months, after which they closed the case without even discussing it with me, and it wasn't clear cut enough to be worth going to small claims. The second time was a cheap Hifi from PC World, 18 months old the amp stopped working. They gave me a load of guff about the warranty I didn't buy, but then wouldn't accept it back 'for investigation' unless I got it independently assessed first. Which would probably cost near to the £80 it cost, plus I'd still have the battle with PC World.
But for a £2000 lappy I'd be prepared for a bit more of a fight.