Preferring bean or processor invocations on a route

I've seen a number of web statements by individuals favoring the bean()
invocations over calling a processor. I believe the arguments / rational
stated is that of simplicity, interaction with other libraries etc.

I personally prefer processor in that it allows me to alter / affect more
than just the result body, eg: properties and headers. I'm not aware of any
means to do this within a bean() invocation.

Can this be done and is there any rational of choosing one over the other?