I stayed in the Carrivagio on the 3rd floor for a week as a fortunate business traveller. Although there are some small irritations (no wireless, and if you forget your ethernet cable, they will 'rent' it to you, which I thought was ridiculous, but I did bring my own) and the fact that although the website says it's a B&B, it isn't, overall it was fantastic. The carrivagio is good for 1-2 people, is on the 3rd floor, and is really spacious and comfortable.
Staying at the west 11th is to be in new york at a calmer, better time. Tree lined streets, culture, cafes and bookstores and cupcakes. I can't reccomend this place highly enough, particularly if you are staying for more than a few nights. Having a working kitchen in an apt in NYC is amazing.
Tips to the owners: Ease up on the scary fees ($500 if you polish your shoes on the sheets, $300 if you lose the key) and change the website to reflect the fact you are NOT a B&B. Include the fact that there is housekeeping every day both on the website and in the room, and create a system by which guests can opt out of the housekeeping, or do it every other day, if they wish.
Final suggestion: Instead of giving guests sheets of paper that include restaurant reviews, rules, etc make a little 3 ring notebook for us - you can put the papers in plastic sheets, and maybe do it up a little!
Another review described the rules as draconian - that's accurate. You sign your life away when you check in. I had the misfortune of having my hair dyed a week before, and stained the pillowcase. I had to endure a few days of relatively hostile notes ("we are holding you responsible for the cost of the pillowcase. do you want to pay in cash or credit?" to which I replied by note "that depends on how much it costs!" obviously. It turned out to be worth $40 but because it wasn't new, I was hit for $25. Sylvia, the caretakers, is really very sweet and helpful, and I think felt badly about the way the owners handled this. Sorry, that's an unhelpful digression.
Overall, worth the money, quiet, lovely.