A brief comparison between the three devices mentioned is as follows - Size
iPad Mini 3 and MiPad
are sized almost similar at the physical dimensions of a little difference. NEXUS 9 is the biggest of the lot. Display
All the three devices have the same resolution of 1536x2048. Nexus 9 has the largest display at 8.9 inches while the other two share a size of 7.9 inches. In terms of pixel density the Nexus lags behind with 281 ppi while iPad and MiPad have a pixel density of 324 ppi. Processor
Nexus 9 and MiPad are powered by NVidia Tegra K1 processor. However Nexus uses a quadcore unit while MiPad employs a dual core variant. Both of these have 2 GB RAM. iPad on the other hand is powered by in house 1.3 GHZ A7 processor and an on board RAM of 1 GB. Storage
The MiPad is available only in a single memory variant in 16 GB . However it is also the only Tab to offer expandable memory slot with support up to 128 GB. Nexus 9 is available in 16 & 32 GB variants while the iPad comes in 16, 64and 128 GB variants. Camera
The MiPad and Nexus 9 have 8 MP rear camera while the iPad has a 5 MP rear camera. Even in terms of the front camera, MiPad excels with a 5 MP snapper. Nexus carries a 1.6 MP front camera while that on iPad is 1.2 MP. However, the camera quality has been observed to be better in iPad. Battery
The battery capacity is almost similar across the three devices. MiPad and iPad have a battery capacity of 6700 mAh and the Nexus has a battery if 6470 mAh. MiPad is found to offer a 10 hours battery backup while iPad gives around 11 hours. Nexus has a slightly lower battery backup. Price
Given the importance on the price point in Indian markets, MiPad has the strongest plus point in its favour. While the iPad and Nexus 9 are priced at around Rs. 30000, the MiPad comes with price tag of Rs.12999. What would I go for?
Well, in spite of the big spec sheet and an impressive price tag, MiPad seems to suffer from a few compatibility issues. Several Indian apps like TOI do not seem to work on it. Even the performance stated to be not so smooth. As for other two devices , the biggest deciding point would be the OS you are comfortable with. The iPad runs on iOS 8.2 and Nexus will give you a pure stock android experience. The price being almost equivalent, the final decision will rest with the operating system you are comfortable with.