I'm a NY'er, born here, lived here almost my entire life. I commute a few days a week by bike but far from all the time, and do a lot of road biking too. I ride the streets, bike lanes, parks, bikeways, all over New York. I never give it much thought. There are certain streets that are known to be bad, and I avoid them, but really not that many. Basically I ride anywhere and just know how to react to situations, traffic patterns, intersections, pedestrians, etc... New York isn't a bad place to ride at all in spite of the assumption that it is.
A few years ago I went back with my bike to one of the few places I've lived other than NYC, Seattle, where I spent eight years, and during those eight years I was a pretty hard-core cyclist. But it had been over 20 years since I'd been back. I was scared s**tless. None of the patterns made sense, I found the bike lanes to not be sufficient, the electric trolleybuses to be scary coming up silently behind you. The hills of course mean that you are struggling a bit more. I found way too many streets with no place to ride. But yet, Seattle is supposedly one of the better cities for cyclists. Even Lake Washington Blvd where I used to do after work rides all the time seemed narrow.
I've also been to Chicago a few times, and I mostly stuck to the Lake Shore Drive bikeway, but ventured out into the streets around Wrigley and found it a bit daunting. I didn't have a bike map there though so I didn't know where to go really. I was in Montreal last summer, which has two-way bike lanes along one side of the street (I saw a thread about those here somewhere), and found that also not so great, and other streets I just wouldn't ride.
What are your experiences?