Honestly my worst experience with doors anywhere on the network has to be on a 185. It almost feels like the door controller had personality (but not in a good way!) - it bongs enthusiastically for a few seconds, inviting you to push the button. But when you do, it had a complete change of character - it thinks about it for a few moments, and, presumably after an internal whinge of "Oh come on, do I have to?", it reluctantly heaves the doors open with an unpleasant hydraulic whine, and the same in reverse for the closure, where, for good measure, they bang shut horribly.
I really don't understand why Siemens let such an overall well designed and constructed unit off with such an awful door mechanism.
The nicest doors I think have to be the Coradia ones, which glide smoothly open the moment you push the button.