ipad air 2 (wifi + cellular)
not every place wifi is fast... I prefer to use my own data plan for convenient and fast.. and I can use it even on the go

cellular has gps

you can convert it to use in car..
http://files.harrispublications.com/wp-con...n-car-audio.jpg

nope I don't like to be so trouble..
the other concern I hv also, your phone battery will drain together with ipad...
then you need 2 cable and 2 port power bank to charge them for long term usage

I have the same thought as most people here whereby we can always tether it to our phone and have been buying WiFi models only for many years. Recently bought a cellular model for a good price and the convenience is really a plus point.

If your iPad only stays at home then yes by all means get the WiFi model. However if your iPad does leave your house, even if it's only once in a while, I would recommend getting the cellular model. If you've never bought a cellular model, try it at least once, then I believe it can help you decide better for future purchases.

Yup, at least you tried so you know for sure that getting the cellular model will be a waste for you. I believe this is the best way to cure this dilemma, get a cellular model and try and if it's not helpful then can decide on WiFi models in the future.