Well, they’re right! Their review on The New York Times is quite comprehensive. Here’s another perspective, but effectively it also means – go any time.
Late Spring (it's no more freezing cold) - you get to see the fresh greens; Summer - but of course, so you can walk around in shorts; and certainly during Fall for some beautiful colors at Central Park (so you can also show off your gorgeous shawls)! Christmas, for those who love the glitz, glitter and glamor - 5th Ave, here I come... so, is there ever a time not to visit New York? Never! :)