I would go to Top of the rocks because for me, looking at the weather sky is clean and sunset with Empire state building view would look awesome. Top of the rocks is North west side of Empire state so you would get a better view. But this is my preference :)
You can't go wrong with either. I also think they're about equal in terms of crowds and lines to get to the top. Obviously, the ESB will be much taller...
I haven't been to the top of the Empire State Building, but have been to Top of the Rock. From the Top of the Rock, you can see midtown and ESB well, but looking north, you just have Central Park and upper east/west sides. From ESB you obviously don't see ESB, but you get views of both midtown and downtown. The Top of the Rock is newer so more modern looking with a cool elevator and glass panes on the roof deck, so consider that difference if you think it will affect how much you enjoy it.
I went to top of the rock in early September, when I went I was all the way up in about 15 mins, very small crowd, I moved easily all over the place , until it got close to sunset time, it then became complicated to get a good spot to shoot.
There are 2 levels outside where you can shoot ,and 1 level inside
On the very top there is nothing preventing the view, except maybe people :) it's the smallest of the 3 levels and does get crowded.
Middle level , it's outside with glass o the edges, if you have a smallish camera or a phone you can squeeze it between the gaps in the glass and shot without the glass
low level you are shooting through windows
Thanks for the input, everyone. I think if we do it, we'll do Top of the Rock. But now we're rethinking things. I have a feeling it's going to be cold up there. We might save it for when we're there during warmer days.
