Dublin Guinness FES
It's a remarkably different beer. While it's no longer brewed in the traditional manner of blending "stale" stout with fresh, it still has a touch -- though more muted -- of "horse blanket" on the nose, along with roasted grain, a vinous fruit note and bitter hop resins. The palate is intensely bitter from the roast and hops, with dark, burnt fruit, while the long, complex finish has roast, hops, liquorice and fruitiness akin to over-ripe bananas.
Sainsbury's has a good beer offering, including Brakspear Triple and Fuller's 1845 and Vintage Ale -- though as these are southern beers they may not be available nationwide. But worth checking.