I am considering going the D500 route but amongst the considerations for me (on a tight budget) is that it has no pop-up flash and I don't want to also have to buy a couple of SB5000's to replace my SB700's.
Are you using an IR trigger with optically coupled flashes or have you gone the SB5000 route? If so, what trigger are you using?
I suppose I can still use my flashes on camera with one wired and the other slaved to it, but really bright sun does make this set-up unreliable. Trouble is, two new flashes and a trigger for when I use them on stands is an 'ouch' for my wallet.