Amazon's 20% off deal makes the least expensive member of the iPad lineup an even better deal than it already was.

The obvious point of difference is in the chipset ... debuted in the new iPad Pro. That offers Apple’s tablet a significant performance gain over other tablets and laptops.

But there are still some fascinating results: owners of the iPad Pro can say their tablet is about as fast as a MacBook Air and that wouldn’t be much of a reach. And the difference between the $ ...