Im usually against everything, but i liked the Bespin 3D matte painting.

On the new Bespin sky, if you change to that sky you have to change the sky on the interior of the set (where han and leia are talking about c3po). Its a very pale sky without clouds.

Also i realised in that shot the roof doesnt look like the one that we see from outside. From outside it looks like a high double roof, and from inside it looks much more simpler.

Also, from inside you can notice some blueish reflection from the bluescreen on the middle of the roof window.