I visited Prague and Budapest way back in 1998, and I have no doubt the hobbying scene today has been transformed by the internet. Back then, I relied heavily on the worldsexguide, but I would fully expect there to be a lot more information available today on the web.
For hobbying, I much preferred Prague... I thought the girls were better looking and the selection was better. Mileage was a bit higher in Budapest, however, and the cost was quite a bit less.
Budapest is a beautiful city, and the Hungarians are a proud, friendly people. There is plenty to see and do, in between hobbying sessions. One of the sights I recommend is a place called Statue Park, which is located just outside the city. It is a place where all of the old Soviet era monuments have been moved and preserved. It is kind of freaky to see, and you can do it in an afternoon.