I use the Platinum holsters as well. I purchased one for my iPhone 5s and gave the case away the first day. Used a Spigen case with the belt clip and loved it.
I now use the holster for the 6+ with a Insignia Clear case from Best Buy that looks great. I understand your dilemma though with the UAG. If I find something that will fit it I will let you know as a friend of mine purchased the Maverick for his