The one I am testing sounds vague just like that even with no iron around. Pin pointing is a barsteward I can see why some people claim they are deep.
I have found if you use Iron Bias 0 you will hear a fair bit of Iron as a good sound so it is not really a fair shout. 2 is the minimum I would use.
My mate is selling his if anyone is interested, collect from Havant / south coast area.