Some of the specs of the iPad mini are better than the Nexus 7 not all.
The iPad mini weighs 0.68 lbs/308 grams. N7 weight is 0.75 lbs/340 grams
The iPad Mini size 7.9 x 5.3 x 0.28 inches. N7 size 7.8 x 4.7 x 0.41 inches.
iPad Mini display 7.9-inch IPS, 1,024x768 pixels (163 ppi). N7 display 7-inch IPS, 1,280x800 pixels (216 ppi)
iPad storage 16GB, 32GB, or 64GB. N7 Storage currently 8GB, 16GB. (Note on 29th release 16GB, 32GB and 8GB model withdrawn)
iPad Mini Camera 5-megapixel rear-facing, 1080p HD video; 1.2-megapixel front-facing camera, 720 HD video, N7 1.2-megapixel front-facing (No rear-facing)
iPad Mini Battery"16.3-watt-hour"; 10 hours battery life (rated). N7 Battery 4,325 mAh; 10.1 hours video battery life (tested).
iPad Mini Cell moden 4G LTE versions available. N7 currently Wi-Fi only ( Note rumor on 29th of 3G cell moden)
iPad Mini color black or white. N7 black.
iPad NFC no support. N7 NFC supported.
iPad Mini Processor Dual-core A5 processor. N7 Processor Quad-core Nvidia Tegra 3.
Price ( will all change on Nov 29th but N7 will be cheaper)
For the record N7 Quad-core Nvidia Tegra 3 is twice as fast as the iPad 3 A5X processors which is faster than the iPad Mini A5.
Video Nexus 7 vs iPad 3 CPU
Nexus 7 vs iPad | Fastest Android Tablet EVER - YouTube