On peak hours, German trains can indeed become unbearable, in either class. So maybe even I would prefer an open saloon car (but I rather avoid taking German trains on peak hours).
When the train is not packed, compartments are much more comfortable IMO. If you feel disturbed by a fellow passenger in your compartment, you can change it - but people sitting in a compartment usually have a better behavior, because it's a difference in privacy. People usually go out of the compartments for making their calls.
But in an open saloon, you just need one single a...hole yelling into his mobile-phone who can spoil the quietness and comfort of the whole car (happened to me the last time when I took the train between MUC and ZRH about 7 years ago - it was an Italian business man...).
Taking the train in Germany was much better about 10-15 years ago, before the mobiles came up...