I'm a member of the Wedding & Portrait Photographers International as well as PPofA, as I'm sure many other PPoA members are.
What do you think about the WPPI's 8X10 Print Competition? Wouldn't this resolve the problem about the bright competition lighting that the PPoA has. I've sat in judging rooms and from the audience area a 16X20 print doesn't look that big so there is no advantage to having larger prints in terms of the perspective of those not judging.
As far as print displays are concerned, quite often the conditions for the display of 16X20s are not ideal, particularly when the prints are so dark. Couldn't some sort of technological fix for print display be found, say on high definition monitors after the prints are digitally captured by a scanner?
If you want to see how beautiful a photographer's work really is the best place seems to be when there are prints displayed during the photographer's program. They are often larger than 16X20 and printed as they would normally be printed.