I've visited this place twice and I'm still unsure of what type of restaurant they are aiming to be.
The food is ok. Not outstanding but ok. The portions are small and a bit overpriced. They also serve several draft and bottled beers but only certain staff members can actually deliver them to the table due to age restrictions, so, beverage service is rather slow.
I've never left Smokin' Willys totally unsatisfied but I grew up on NC BBQ, ribs and sides. No doubt the place is doing better than the restaurant that preceded it in the same location but its not at the top of my list in Purcellville.
Give them a try, see what you think. They do deserve that much and can only get better as a result.