Cortana is Window’s answer to Siri and it’s pretty useful when you need to search for files or the web. For designers like me, Windows touch screens are a godsend. Apple only has mobile iOS for that.
But when you’re working with 3D graphics, you can’t beat a touchscreen desktop. I doubt Apple will change that with today’s launch. Computers are only 13% of their profits.
But if you walk into my office, I have four Macs and only 1 PC. So bottom line: Mac will always be reliable for design, but for specific projects check out Microsoft.