When Greene King experimented with their St Edmunds Ale a couple of years back with their Northern / Southern pull contraption, I tried a pint of each version in the Dog & Partridge, Bury St Edmunds. Both me, Mrs B and the mate I was with preferred the the northern version with the head. Chatting to the very lovely but typically dopey barmaid (as you do), she informed me that most people in the pub came to the same conclusion. Of course, the other 99.9% of the drinking population prefer another brewery's beer altogether but that's for another thread.