I have the Symmetry on my Space Gray 6 with a Zagg HDX protector. I love it as well!
I usually to thru a LOT of cases, but I might have hit it on my third for my iPhone 6 Plus.
The Powersupport Air Jacket in rubberized black is close to perfect for the 6 Plus. Very thin, great feel, nice fit. Makes the SG iPhone look like a black iPhone!
If I want more protection I go to the Apple leather case.