My family of five (kids age 3, 5, 7) drove up from DC and stayed here with our friends, another family of five (kids age 1, 4, 6) for the long weekend in October. The house was REMARKABLY well appointed, we didn't lack for anything. The bedrooms were spacious and laid out so as to keep lots of open floor space. The family room, dining room and game room were all the room we needed and then some - plus an eat-in kitchen with a built-out porch! - we never even went into the cavernous basement. This house was designed for entertaining! Super comfortable, great living space.
The community of Arrowhead Lake seems to have a lot to offer visitors between the events and activities going on each day in the main lodge and all the lakefront beaches (each with parking areas and playgrounds on/near the sand) and swimming pools. I wish there were walking paths or hiking trails to enjoy the woods, but you are walking on the roads to get around anywhere within the property.
Great place, 45 minutes drive from Shawnee Ski Mtn. Closer to Jack Frost. Really quick, painless commute from DC.