Ipad Pro 9.7s dropped in price recently. Been thinking about one to fly Phantom 4 and in the near future a Phantom 4 Pro.
Any issues?  I normally fly with my Iphone 7 plus, but there are times when would like the phone to use for video and other things.  
Do I need a different holder if I go with the Ipad Pro?

I have used the iPad pro 9.7 without any display related problems with my P4 and all the latest firmware and Apps. It fits snuggly into the GL300C device holder, with a couple of clicks to lock it firmly into place. I also use it with my Mavic with an additional device holder that is needed.

I think the older iPad Pro 9.7" is about the same size as my Air 2 which fits with about one-click's worth of tightening.

I bought the newest iPad Pro 10.5" A10X 256GB with cellular and it will fit,  but it's very tight and might be better if one removes one foam tape from one of two clamps, or use once of those slip on extension things for about $15 off eBay.  DJI needs to widen the clamp a bit for some of these newer tablets, imho.

The maximum width of P4P holder is 170mm. You may consider a different holder if it is not convenient for your tablet.

Thanks everyone for the input!  Very appreciated!!!