I've been looking at this and wondering what to suggest to help. I think that a touch of silver mixed into the base coat and thouched along the edges would bring up the armour. Personally I'd use a steel metal on the blade edges and you could use it on the rivets of the armour as well. Having said all that I know what a difficult figure this one is to paint.
I'm sitting here wondering what colours you use. And also how you undercoat your minis. Sometimes a great way of improving is to undercoat your minis black. Because than you'll be forced to work all the way up to the brighter colours, creating depth as you go.