Trouble with Barolo mate is that it's intrinsically expensive stuff (for reasons I know not why), so to sell it for £10 - £15 a bottle, the supermarkets have to sell you the worst crap available. More often than not, I've found a £12 Barolo to be borderline undrinkable. The same goes for Brunello di Montalcino (aka Brunello), and (to a lesser extent) Amarone. (And Ribero del Duero on the same theme.) These are all wines that come into their own at a higher price point than most supermarkets want to sell at.
Spend £25+ on a Barolo and they start to get very good. At £50+ they can be amazing, but it's a long time since I dropped £50 on a bottle of wine.
For £10 ish, you're better off with a worse wine, if you know what I mean. A Valpolicella Ripasso, for example.