I have to admit, I am very entertained by 'draught' cans. The pop, the schnick, the whoosh. Guinness, for example, has done this for a few years, which adds a nice head to the beer, Murphy's Irish Stout and Boddington's Pub Ale too. I don't know exactly what that little ball does, but it does pour you a foamier beer.
Last May I reviewed Belhaven Scottish Ale, and enjoyed it quite a bit. Belhaven does have a slightly different line for export from what they sell in the UK, and now their Scottish Ale comes in a draught can. Last May I said the Scottish Ale reminded me of a porter, I could swear this stuff is a whole different creature. This guy pours with a nice fluffy head and deep amber color, seemingly without hops and very malty. It reminds me, actually, of Boddingtons, except darker color, more malty and tastier. More expensive too, and a lot more expensive than the same Belhaven in a bottle. My wife says 'it hugs your tongue', probably because dinner was spicy, and I say this is a great beer but - as I might say with many beers - a few more hops couldn't hurt.