Galaxy note 10.1 or ipad air?

Hello everybody,

I am planning to buy a tablet for college. Given that I am in engineering, it will be used for a lot of note taking, photographs,reading PDFs and some graphic design work. Obviously, I will be watching a lot of movies too,but that is secondary. I already have a windows laptop and it is used for all the heavy duty work. But, for the tablet, I am torn between the Air and he gNote .

With all the research, I am fairly sure the note would suit my purpose well. But I will be using it for the next 4 years, and have doubts that it will last that long (being a Samsung device). I am also worried that the lack of tablet apps on the play store might bite me some day. Yes, I can find every app that I need right now on the play store, but it is possible that some unanticipated need pops up and there is no app for that.

The ipad air is perfect, except that there is no decent stylus support, and I don't want to splurge on a stylus. The lack of a file system and sd card support would be another huge constraint (pretty horrible internet coverage where I live).

Which one would you recommend? Will the note 10.1 be usable after 4 years? Is there anything on the App Store that is irreplaceable (from a students perspective)? Finally, which is the better device,in your opinion?

By the way, I am not looking for any windows device. I already have a Lumia 800, and didn't like metro at all. So,no RT for me.