There are some excellent proposals in this thread; I'll just throw in my 2 cents worth. It would be ideal to identify the winners earlier in the show, much as happens now in Telford. I do think there would be some propensity for those who didn't win to pack up their models. They might not leave, but there would probably be gaps on the tables. If that doesn't become a trend, it probably wouldn't matter.
I personally enjoy the awards presentation. As an aircraft modeler I concentrate on those categories, but I also would like to know what won in other areas. During the usual hustle at the show, you may not get to every table. And probably 20% of the winners shown during the awards presentation prompt the expression "I didn't even see that"! However, the banquet has become too lengthy. We have added categories, specials and recognitions over the years and this now taxes the patience of many in attendance. Even with our proud graduates of the Evelyn Wood Speed Speaking Academy, Aris and Bill, there is a LOT of ground to cover, and they do it exceptionally well. The two-tiered system mentioned by Gil and Don is definitely something to consider. I like the idea of a speaker and recognitions being done on Friday and the final judging results on Saturday. The logistics of assembling so many people twice during the convention would have to be worked out.
Some things, from my perspective, may not work. The Telford arrangement, where models are intermingled with vendors, is attractive. But these are SIG and club display tables. Their members are in attendance continually to talk about the models and the special interests they represent. The competition room is just about as far from the common area as possible. Since they judge during the day anything else would be a nightmare. Yes, the Nationals ain't broke. The numbers of attendees and their enthusiasm seem to increase every year. So the system doesn't necessarily need to be fixed, but as others have noted, it has evolved to get it where it is today. To think that we have achieved perfection and don't need to consider improvements or alternatives, is naïve at best.