I have 2 Xbones with instant on and open NAT.
Xbox One - Day One Edition directly wired to DGL-5500 - OPEN NAT with 'INSTANT ON'
Xbox 360 directly wired to DGL-500 - OPEN NAT
Xbox 360 directly wired to DIR-868L (used as an AP) - OPEN NAT (DIR-868L wired to HP Network Switch - HP Network Switch wired to HP Network Switch - HP Network Switch wired to DGL-5500)
After Santa arrives with the second Xbox One - Day One Edition, it will be directly wired to the DIR-868L (used as an AP). Once I get it set up, I will check to see if I get OPEN NAT with 'INSTANT ON'.