Siri on the Mac's new Sierra OS: so-so

NEW YORK--Only a few years ago, the launch of a new computer operating system set off impassioned clashes between devotees of the Mac and supporters of Windows. Tuesday's arrival of macOS Sierra seems like an after-thought by comparison, coming with nowhere near the media attention that's paid to an iPhone or even iOS release. The marquee feature is Siri's debut on the Mac, and while this is mainly a welcome if long overdue development, the fact is we all got to know Apple's loquacious personal assistant on the phone first. Indeed, with Sierra comes further evidence that we're fully entrenched in a post-PC world, where the computers in our pockets have trumped those on our desks. Microsoft with Windows 10 has for the most part designed a single operating system that is meant to work across PCs, phones, tablets, even Xboxes.