This has always been a problem for me as well. But, as far as I have been told from mitel 2nd / 3rd line, this is the way it should be as in call centre environments, the agents need to know what call is calling in order for them to make the right introduction.
However, it is not just call centres that use ACD and they would like to see the ANI instead of the Path Name.
The only way round it I have found is that the higher end sets, show both.