looking to replace my android tablet with a ipad or ipad mini4. Looking toward the ipad as it has a faster prosessing speed and is newer. will the ipad work ie no issuses or is the ipad mini4 a better choise?

Either way, you'll have an impressive flight kit to play with.
For my dedicated device of choice, I have an iPad Air2 Cellular, which has been stellar.

I think the bigger screen will always have it's advantages.  The higher processor speed  is a desirable component as well.
If you want to change your dynamic home point, while traveling during your flights, and use Follow Me feature, I would advise going for a unit with Cellular capability,  which brings several advantages, even without a Cellular plan. If you get a plan, then you can also stream live video feed from your drone to your FaceBook account, or to your own YouTube channel.


RedHotPoker

The Mini 4 works well for me.  It replaced an android tablet that was slower and had issues.  I also had a mini 2, but its slower and doesnt have the anti glare coating.

I would suggest you to check the recommended list: http://www.dji.com/phantom-4/info#downloads