looking to purchase a dedicated tablet for my P4 should I get an ipad mini with data servise or not???
or what do you recommend

gracias In advance   

Depends what you want to do with it... Ipads doesnt have GPs, so the active track feature of the P4 is limited to wifi distance

but an ipad with data does have GPS

Hello, here is a list of our support device. Since the iPad without data service doesn't have a GPS module, it cannot support the functions which need the mobile devices' GPS signal such as Follow Me

Cellular internet access will allow you to Download maps real time and stream live video to Facebook or Google when you're away from WiFi.

The GPS capability that comes with cellular iPads will allow you to use the 'follow me' option.  (Although 'active track' is probably just as good).

One nice thing with GPS is that you can see where you were standing when reviewing the flight logs. Your location at the time is shown as a blue dot.  If you try something like flying from a moving vehicle, you will be able to follow your motion in relation to the craft when reviewing logs.

If you ever decide to run the Litchi app, it draws a continuous red line between you and the craft on the map.  Not a big thing, but I find this helps with orientation.

The cellular & GPS option adds about $100 to the cost of an iPad. But, if you want to save a bit, you don't have to activate a cellular plan. The GPS works OK on its own. You just lose the data capability.

Data costs vary. My cellular provider allows me to add the iPad to my plan and draw data from the same pool. It costs me an extra $10 per month.

I use my cellular iPad Pro 9.7 for much more than flying.  I've been using iPads with cellular data for years.  I like being able to browse the net or stream audio when I'm out without having to sniff around for a Wifi spot or tethering it with my phone.  I use it a lot for GPS navigation in my car.  The big 9.7" screen is great to look at. It beats phones and dedicated GPS devices.

To me, an iPad with cellular capability is 'worth it'.  If you can afford it, go for it