That's just my experience, but I have a Mini since January 2012 and I love reading on it. The only down side is the lack of light. i'm taking it everywhere I go
I've had an Aura for less than two weeks and in the end I returned it because I didn't like the screen resolution. I'm one of those who think that the flush bezel hampered the overall screen quality.
If you want light, go with the Aura.
If you don't really need it, consider the Mini.