The Hotel Marqueses is located almost on the Plaza Regojico (Kusipata) and just slightly farther from the Plaza de Armas. It's centrally located to everything you'd want to see in Cusco and the street is accessible to cars, so you can easily access taxis to more distant places.
The hotel is in a centuries-old building and has historic art on the walls. The two courtyards of the hotel are really beautiful and I got a good feeling whenever I walked through them. The Marqueses is neither stuffy nor chic, so it is a good place for kids, although there are some ledges and steps, so have very small children be careful. I thought breakfast was better than most of the other hotels I have stayed at in Peru, with lots of fruit, tea, and bread options and plenty of space to spread out in.
I like historic hotels very much, but this hotel needs renovation. The carpets are threadbare, metal fixtures have rust, and showers spray water onto the floor. Some people would like having a room with a skylight, some people won't because it will wake them up early.
We still had a great visit to Cusco, but some people might be bothered by those deficits.