Is NY really that dirty? I visited for the first time in a couple years last month, and given all I've heard, I found it surprisingly clean (about the same level of cleanliness as SF, where I live).
I'd say it's pretty dirty. The subways are disgusting and the streets often have trash strewn about. SF is certainly not that much better (though the BART stations are far cleaner).
I've been to a number of major US cities, and lived in 4, and NY is by far the dirtiest city I've seen outside the third world. The sanitation system is non-existent. There are no alley ways or trash bins, so there are just bags of garbage littering the streets. It's surreal.
Seattle and many other cities have parks spread across the whole city, and one central trash dump.
In Manhattan, vice versa.
Not true. I lived in both Seattle downtown and Eastside. Just in the 15 streets around Union Square area there's the Union Square, Thompkins Square, Gramercy, Madison and Washington Square parks plus at least ten smaller parks or playgrounds. Try to find a green playground in Seattle downtown.