I have an android phone, a 3rd generation Ipad, and a Nexus 7. I use the Ipad about 80% of the time and the Nexus 7 20% of the time. This is strictly because of screen size. If the Nexus was a 10" I would probably use that more than the Ipad. Both are about the same speed, have the same apps I like, etc. the one thing I like about the Nexus is that it's a lot more customizable. For example, it allows me to change to another keyboard.
The only time I prefer the 7 to the 10 inch is when I'm not home, which is about 5% of the time.
the mini would be my last choice. $300 to $450 is ridiculous.