I have purchased the duplicolor red and silver kits and I was happy with how they came out. The one thing I do know is that when I took intake manifold cleaner (stronger than brake cleaner IIRC) to my calipers before doing the silver, a few seconds after I sprayed the red paint was all bubbling and I wiped the duplicolor stuff right off, exposing the darker red G2 caliper paint underneath.
I haven't had any caliper paint on long enough to really test the durability (I'm fickle) but I think I'm all set with my silver front black rear so I'll see how that holds up.