I just thought I would share my recent experience with homebrew contests. I recently did very well in a couple, and entered the same beers in several contest for comparison and to obtain a wide swath of input.
I have learned a lot. I thought that this may be a good place to share info with those who already enter comp's, or those who are thinking about it.
NHC: scored 39.5, advanced to the second round - very good feedback. I can taste what the judges taste, and was happy with the score. This beer will be better next time.
Oregon homebrew contest: scored 24 - not to style, Diacetyl present, no hops or bitterness, smelled like rice: too many flaws.
My take: large difference in score and a tough category. I have found that it really depends on the order in which malt/hops combination in beer follow one another - for example, If I drink one IPA, then drink another (that I always love), the second beer can taste like crap.
Lesson to be learned: Take the bad with the good, and understand that there is luck involved. IPA and IIPA's are tough to judge a flight of. I think I may have suffered from following the wrong beer in OR, but may have been luckier in the order of beers during the NHC comp's.
Hope this helps others as much as it helped me.