It's funny that you say that as I'm leaning towards 'heavy' for exactly the same reason. You just don't see that many of them. I'm stealing armor bits from clones, stormies, the Predator, whatever... to make my design heavy but still rapidly mobile.
As for military vet, my objective is to make a set of armor as 'heavy' as possible while still being able to move comfortably and quietly. A Mandalorian warrior in constant conflict would most likely have made that same compromise over time.