We stayed here for a short weekend away from DC. There are multiple grocery stores a short drive away and we bought firewood at the KOA store. The house was clean and the kitchen is fairly well stocked. We had 8 people and there was plenty of plates, cups, etc for us. The bedrooms are great for group trips, four are basically the same size with queen or king size beds and the other room with 4 singles would have been good if we had more friends or a family with children. Bathrooms are good sizes and in good condition. Plenty of parking for our 3 cars, if you wanted to squeeze you could probably fit 8 on the driveway.
We hiked one day we were there, the Harpers Ferry visitor center is a quick 10 minute walk down the road from the house and from there you can take the shuttle into town or get onto a number of hiking trails. Definitely would recommend staying here if you're looking for easy hiking access and want more amenities than camping. We were there in the winter but in other seasons we would have been able to use the KOA pool and mini golf right next door.
Overall we'd recommend this house for group or family trips! Bonus - pet friendly!