Both Tablet PCs are class in itself. Not much to think about it other than OS. If you are neutral about OS then both Tablets are good. But Nexus 7 is far cheaper than IPad Mini.
Google's Nexus 7 -
- Better Processor
- Better customization,
- Easier File transfer between Laptop/Desktop,
- Better pricing,
- Better resolution (216 ppi) vs Mini's 163,
Apple's IPad Mini -
- GPU is better,
- Weight is unbeatable, only 308 gm Vs Nexus 340 gm,
- Camera is far better in IPad Mini. Two cameras, one with 5MP and another with 1.2 MP. Nexus has 1.2 MP front Camera only.
- Battery is slightly better in IPad Mini.
Apple IPad mini uses iOS 6 and Google Nexus 7 is using latest 4.1/4.2 Jelly Beans.
Nexus is 7 inches and Apple IPad Mini is 7.9 inch screen.
Many times, you may find Apples app more optimized than Android's one for tablets. But you have options there.
Size and weight is not much different but for reading, 7" is better with higher ppi of Nexus.