Well, I flew it today, and had a great time! Extreme clear conditions, and a little bumpy. Departed KFRG runway 32, left downwind to the south shore. From there, I contacted JFK Tower 125.25 and requested South Shore at 500, VZ climb to 2000, Hudson, Central Park, Throgs, checkout eastbound. I was told to proceed as requested, and got clearance to climb to 2000 and enter Class B airspace just after passing west of JFK. I was handed off to EWR tower, and went over the south tip of Governor's Island and on up the Hudson. After passing the Lincoln Tunnel, I was handed from EWR to LGA tower. LGA told me Unable to proceed to Throgs, so I remained on the Hudson and didn't cross Central Park. Just north of the GW Bridge, I asked for and got a course reversal to return to KFRG the same way I came. LGA handed me back to EWR, and EWR passed me back to JFK south of the VZ Bridge. I checked out near the Jones Beach monument and climbed to 1500'. FRG tower set me up following the inner shoreline for left base to 32. Total time 1.5h with runup and taxi, cruising around 100kts.
I had the Helicopter Chart with me which gave me a lot more confidence following the routes and being flexible if I was given a different routing. Also, from listening to LGA and JFK tower quite a bit I was familiar with the VFR callups for Class B routing, so I was a lot more comfortable with making my request. All in all, it was much easier than I thought it would be and really enjoyed it.
Jason, my experience pretty much mirrors yours. It was great flying the Hudson at 2,000 and staying above all of the local operations and out of the SFRA. Hopefully next time I can get Central Park and Throgs routing back so I can fly over the LGA cab.