There is more to NCOWS than just shooting and that is one reason why I prefer NCOWS to SASS or other outfits. Regardless of where the emphasis is made in the by-laws, the stress on "authenticity" and history is a definite distinction, and the main reason I find NCOWS more interesting.
I was a living historian and reeactor for about 20 years prior to getting involved in CAS. Consequently, I'm heavily focused on the "authenticity" aspect. Comparing both SASS and NCOWS, I was more impressed with NCOWS' stress on authentic clothing, firearms, etc. However, being back East there weren't any NCOWS posses to join and shoot with, so I joined SASS. Not long afterward, I came across an issue of the Shootist and liked what I saw, so sent my membership in to NCOWS.
My only NCOWS shoots have been the two GAF Musters, but I have to say they are two of the very best shoots I've attended. While I wore a uniform (it was a GAF event after all), I was very impressed with the outfits worn by the "civilian" participants. I also like the 10 sec penalty for missing. If it were a real gunfight and you missed too many times, the penalty would be a lot greater, so hitting the modern day shooter with a 10 sec penalty seems fair enough.
As Chantilly and Maj Matt Lewis have pointed out, the "attire" competition (I associate "costumes" with Halloween so dislike the word) was very competitive. Almost all had the basics nailed, and most had progressed well beyond that. I need to make a much more detailed check list for next year's competition, which I expect will be even tougher than this year.
Chantilly is also being too modest - the dress she wore on Sunday was very impressive and could have easily won an award had she been in competition (we judges took ourselves out of the competition).