This house is located in great spot of the peninsula, 20mn walking distance from Portofino and 45mn to Santa Margherita. Even if the house is down the main road, we didn't hear any car noises. It's quite spacious (3 bedrooms and 3 bathrooms) with a big living space which open on the small cove of Niasca. We loved having breakfast and dinner there, with the sound of the waves on the background and the view through the huge french windows. The size of the house is really nice for 6 to 8 people.
We stayed on the lower level of the house (the top level was rented to another family, and below was Watersport services which open at 8am, very nice people). The top level of the house gets the chance to have a private space on a flat rock but we didn't had that chance.
Therefore, because there are almost no public beaches in the peninsula, this cove is crowded from 9am to 7pm. We expected that it would be public but not that crowded. So if you don't put your towels and kind of reserve your spot early morning (8am), you won't find any space although you're just in front. We recommend the right side of the beach as you get the sun all day. And you don't have a direct access to the beach, which is a problem for the kids as the can't cross the road alone.
The house is very charming but needs a serious refreshment and therefore, I have to say the price paid is really high for the amenities you get: for example, last bathroom does not have a proper water pressure and if somebody takes a shower in the other 2 bathrooms, the water is cold. To be honest for the same price/night, we had a luxury 4 stars hotel in the best area of Florence and for half price, we got 3 big bedrooms in a fantastic agriturismo with high comfort, breakfast included, all modern amenities.
Regarding the activities, We recommend to walk toward San fruttuoso by the pathway, it's a lovely journey (lunch at La Cantina there), in Portofino, we liked the beautiful restaurants "Magazin" (wonderful Fish) and "Tripoli" (best Pesto ever) and enjoy the fresh fish market of Santa Margherita (from 5pm). Of course, enjoy some watersport just downstairs in the protected bay.