Mission accomplished! Let me know what battery grip you get and how it works. Haven't had time to research any. The XQD cards have dropped a lot but are still $65 for 32GB. They are blistering fast when ingesting them into my computer. I use these: Sony 32GB XQD Memory Card G Series 400MB/s
I'm going to wait for the prices to drop a little more on the XQD cards. I hear they're a bit more rugged than SD cards. There appear to be several brands of battery grip on Amazon. I have a Zeikos for my D300/D700 that I'm happy with, but they don't make one for the D500.
The XQD Cards are indeed a good bit more rugged than the SD cards, in fact I find them more rugged that CF cards as well. The key is you cannot get the full burst rate performance experience with the SD card, no matter how fast it is. To truly get the benefits of the burst capabilities you really need to have the fastest possible XQD cards. I went with Lexar 2933x and I've been extremely happy with them. The Sony ones seem to be reporting good results in the market as well.
Once Nikon comes out with the iOS app so I can download to my iPhone direct from the camera, I will go fully XQD. Right now, I have to use an Eye-Fi card to do the transfers as my clients expect pics during games.
I don't know if any of you noticed, but Nikon released a minor D500 firmware upgrade on Nov. 8. You can get that and all kinds of other stuff on the D500 download page.
As part of Black Friday, some Nikon dealers are bundling a free battery grip with the purchase of a D500 or D810. It looks like I bought my D500 a month too soon.