I went today. First time I have been to that location.
Nice facility for the show. Wide aisles, lots of seating if you want to rest, clean, free parking, well lighted and well ventilated.
I would say the layouts and their associated space areas took up about 25% of the floor space. About 30% were folks that had all or majority of their items in O Gauge. Remainder were HO, N or something else. One guy had a ton of S Gauge. It was really nice to see - well presented. He might have had 5% of the selling tables just by himself. I like these shows because it is a lot of different items and I like to see the other scales.
So, without getting into a political discussion, we have a economy that is barely growing (and probably in a recession), we have sequestration hitting the DC area as of last Friday (ergo, no pay checks for people), and it was cold and overcast. Those were probably factors that played into the crowd, buying habits (or lack thereof) and mood.
I was more than pleased with what I saw. Went into the show with intent to buy nothing and spent $10 on a car/trailer for the layout.
I did see a few folks that I saw at York. J&R Trains (from PA) who rivals Trainworld on pricing for Williams; B&B Hobby Supplies - who also has ETS trains at really great prices; and a guy from Ocean City NJ with a lot of HO items (can't recall his name).
Overall, I thought there were some great items at very good prices. One just has to be patient and look. For example, I found a guy selling MTH cars for less than $30. It was not primary item he was selling and 'off to the side' of his display.
I would say this is definitely smaller than the Greenberg show at Dulles, but if you go to these shows expecting little in the form of O, then you are set for some nice surprises. Not a knock on the show or organizer, just my personal approach.
If one wants predominantly O, then one must go to York.