What tablet should I get when i enter university?

Hi, i'm going to university in few months and I need a tablet for taking notes and documents and others
I've seen lenovo and nextbook and optimizer some that have sim card really caught my attention. But i'm not really sure because I don't know what features I should be looking for. Any suggestions?
Ps my budget is 300 to 400 $

Ipad

There are two that I recommend. Both have special pricing for students

Microsoft Surface Pro.
Macbook Air

The Macbook Air costs a bit more, but has an integrated keyboard and is better quality construction all around. The Surface Pro is the least expensive tablet I suggest for a student.
What tablet should I get when i enter university

Be careful with SIM only tablets they can get expensive when you realize you need another data plan. Wi-Fi devices that also have tethering (can use your phone's data plan wirelessly) may be a better option.

I have a blackberry so my playbook is pretty handy and dirt cheap. Alternatively the low end microsoft surface is really powerful for it's cost.

Cheers and Good Luck