BGN bodies typically can vary. The two BGN grade F4's I've owned have been somewhat worn. One of them did have a mode switch issue that they gave me a $30 price adjustment, since I had no guarantee that the replacement body would be a later body, less likely to be flaky. The other works perfectly, just has some wear on the dials, etc, and the body finish isn't matte black anymore, instead, it's rather shiny. I've also owned a BGN grade F2A that, except for a couple tiny dings, would be very close to what I'd think they would call EX grade. Very tiny amount of brassing.
Lately, I've been enjoying buying AS IS gear off their eBay page. Got a lot of six supposedly dead Nikkormat FT's and Nikomat FTn's. Only one was truly dead. The rest did fire, and two FTn's had properly working light meters as well. Kept those, and got rid of the rest. One will be used as a donor camera for my Nikomat FT2 that needs an overhaul, and the other is loaded up with a roll of Ektar 100 as I type this.
-J