Sandy,
Jim, the keeper / ranger / can't remember his full title at Milbuies is a really nice chap, very helpful. It is a rainbow fishery though and very narrow – probably about ½ width of Haddo over most of its length. Very sheltered, very shallow, good boats – boat only. There is also a brown trout fishery at Glen Latterach (sp?) stocked, but with wild fish too. Very windy and exposed. Permit info from Milbuies