I rode it this year, so much fun! Aside from the start - it took at 1.5 hours to go the first 4 miles up 6th Ave, but once we got through Central Park everything was fine. Like eleanor said it's completely flat, and the only time there were small hills were on the bridges, but due to back-ups caused by out of shape people walking their bikes up the bridge, we ended up having to walk up too. But it was so much fun and riding my bike over the Verazzano bridge at the end of the ride was SOOO COOL!!

I had done the NYC Century Bike Tour last year, which is much small (only a few thousand) and they don't close down the streets, so it's a totally difference experience. Both were fun, I'd suggest doing either of them at least once, it's really worth it.