We stayed in this home with two other families. The house was great, with modern furniture, appliances, and features throughout. Lots of room to spread out and sit - including large back porch (both a shaded portion and a sandy sunny portion) and inside TV, living, and dining areas (easily sat our group of 10).
Beach out back was great for small kids - clear, shallow water with very little surf, and warmer water than the ocean side (kids had no problem swimming, but adults still found it cold). Large tidal change exposed lots of sand for exploring at low tides - crabs, shells, oysters, etc. abounded. House also came with two kayaks which the kids (and adults!) loved and kept busy. All easily visible from the big porch too, so easy to keep an eye on the kids.
Location was maybe a mile walk from downtown Provincetown (sometimes we'd walk down, but then have someone pick us up). You can drive, but parking is not easy. P-town is very interesting, very dominated by the homosexual culture, but we had no problem bringing our kids down there, and there was an art gallery on almost every corner, and lots of interesting shops.
We did have a significant issue on arrival that the air conditioner malfunctioned during a very hot time, but the property manager was very responsive in getting it fixed ASAP, and the owner even came by with some fans and some cold beer "on the house" to accomodate us as comfortably as possible.