Not to muddy the waters but I have had good success in using a displacement and normal maps together from Zbrush (chest armor), I had to be judicial in my use of each and not over do it but basically the displacement was my workhorse and the normal helped refine the detail...this was suggested to me at Zbrush Central by several members.

I have also found that a displacement at 4096 did render better quality than at 2048, not trying to pick a fight but my test did show better results, perhaps it was just my particular project scope, maps were created out of Zbrush at 4096 for all maps.

Normal and displacement maps on Chest Armor. Normal maps on Boot Armor.

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