My perspective is somewhat different. We live in a building on Margit körút less than 200 metres from the Buda bridgehead (pretty much just upstairs from the Bem cinema, for locals). We're anticipating that traffic out front will drop dramatically, which will bring relative tranquility to a neighbourhood whose traffic levels are not a big selling point. Our view is also coloured by our lack of a car. The planned traffic changes would only seem to benefit us.
One thing that isn't clear is how the closure will affect bike and pedestrian traffic. We've heard so many contradictory rumours about it. The latest news on City Hall's website doesn't mention this aspect although a May article in Index.hu quoted Mayor Demszky promising that bike and pedestrian passage will be ensured throughout the project. I hope he hasn't reversed himself, as he's prone to do concerning important cycling and pedestrian issues. Living so close to the bridge, it'll be easy for me to follow how it really plays out.