I've had more Murphys' than most people on the planet & I've had some rough pints
too. From cans the taste of Murphys is - to me at least - "rougher" than on
draught in England. I've never found that the taste varies in cans, as you would
expect, but from a pub it can range from very thin, to badly poured with
half a pint of head.
I worked in a pub last summer vacation (holiday to us Brits) and Murphys seemed to
deteriorate after about 7 days or so, and as kegs (or whatever the term for it is,
not cask certainly) for Murphys (and Guiness for that matter) are expensive there
usually follows a period of sub-standard Murphys.
Of course if smaller kegs were used, or turn over was greater there wouldn't be
a problem.
It's a shame you can't experience a good pint in a pub, because it can be very nice
indeed - much nicer than Guiness!
Marcel
By the way, have guiness patented those 'widgets'? In Britain there are several
types of so-called in-can device - Whitbread use the 'Draughtflow' system for
instance, wheras John Smith's say 'a widget'.
Who cares - it all works.