The apartment was perfect: very comfortable, stylish new furniture and fittings, nice bathrooms, in a brilliant central location, and reasonably (though not totally) quiet at night - we loved the gondolas coasting right past the end of our little street. It really is only 5 mins walk from the Rialto (tourist area and water bus stop) and 5 mins walk from San Marco.
We found and enjoyed some very nice cicchetti and wines in the vicinity - but you have to be wary of 'tourist trap' restaurants with poor quality and high prices. We found Dorsoduro and Accademia were less crowded and more relaxing places than San Marco. Water buses are an easy way to get around, and good for sightseeing - and the 2/3 day pass is good value.
We took a half-day guided tour canoeing in kayaks - starting and finishing on Certosa Island, all around the Arsenale and the canals in the Castello and San Zaccaria area - and this was really fantastic. Details on venicekayak.com.