Reckon this kind of thing is essential to understanding what diacetyl, etc is.
Comps can be harsh (and wrong/flawed) - some diacetyl is acceptable in many british styles but usually a small amount (according to BJCP guidelines which is only one small aspect of where beer styles are, from where they have evolved and what they should be).
You may still make a tasty beer with loeads and find it attractive - no-one else can tell you that it's wrong - it just won't win a medal in a BJCP sanctioned comp.
Follow link under Upcoming Events on front page: www.beerspace.com.au
Also posting in the retailer section of the forum about other seminars coming up in the next few weeks.
(Take your point Wolfy re biographies - will be posting those soon - its a labour of love rather than money - we still have day jobs so will slowly make improvements to the site especially in response to feedback like yours - Cheers)
I was at the first one too and I found it definitely worth the $40 - there were even some nibbles to go round included in the price (debatable whether this is ideal when trying to pick subtle faults, but hey, I was hungry and the food went down well).
George was a good presenter and I was really surprised that some of the faults, which were doctored at 3 times common perception thresholds, were as subtle as they were.
Makes me think twice about breaking my competition cherry.