The climb is an attraction on its own terms: it is tiring, claustrophobic (narrow spiral staircase), and may trigger scare of heights, and on the way back causes head spinning. Even though we weren't in high season, the queue to ticked office was 10 minutes long and there were often trafic jams.
Views are a bit disappointing too: the platform is protected with pretty dense net, angle of view from windows is restricted rue to thickness of the wall, one can look only on the western side so against the Sun in the afternoon and most of the city is typically German well laid grid of cubical buildings.
Out of that the bells chamber seems to be the most attractive - I'm not sure if tourists are allowed to stay when they ring, but that would be truly thrilling experience.
I would recommend to try it early morning, to avoid crowd and have good light for Rhine views. Then walk across Hohenzollern bridge across the river for views of the cathedral.
