iPad Mini vs. iPad 4

Yes, I know there have probably already been a myriad of posts/questions on this topic but I cannot seem to find one that answers my question without either a bias or addressing all my questions. So I am a high school student and I want to be able to use an iPad in school and it also needs to be portable enough. The question is which one? I would be buying the LTE version as well and "waiting for an iPad Mini with retina display" isn't something I want to do either. So my questions are as follows:

Is the screen real-estate/speed/screen/etc... really worth the extra $170 or so?

Is the iPad Mini big enough to take notes on with a stylus or is the 4 better for that?

Speed wise the iPad 4 is clearly (based on Geekbench) much faster than the iPad Mini but is it noticeable?

Is there a difference when reading books/how does text look?

Does not having a retina display detract from the experience at all on the iPad Mini?

After picking up an iPad Mini does the iPad 4 seem just as portable or less?

Would something larger than a 16 GB version be necessary?

What's your personal preference?

Any input would be great even if it is a link to a review or another post or whatever--doesn't matter to me. Thanks a lot!