I've had the Metalline weapon property recommended to me but I'm not sure what bonus that gives better than the Transmuting weapon property. By the reading I'm getting of the Transmuting property it is at most one round slower in switching metal types (about what it is for metalline if you do not instantly know the metal type needed? Not sure with that) however by the reading of the Transmuting property it simply 'Takes on the properties required to overcome the creatures damage reduction' without mention of metal or such which could include things like alignments, epic, and so forth would it not since they are properties that are required to be overcome?