iPad Air or iPad Pro 11: which is better?

Which is best: iPad Air or iPad Pro 11?

The problem for anybody developing a computer device – whether it’s a desktop, laptop, tablet, iPad, or smartphone – is to produce a machine that is correctly balanced to satisfy the demands of its users at the price that is being paid. This is not a precise science. It is determined by the cost of main components such as the CPU and memory. Also the screen, graphics, storage modules, operating system, and so on. You trust them, however, not to burden low-end devices with the cost of high-end CPUs, or to jeopardize high-end devices by offering insufficient memory and/or storage space.