I've been heavily invested in Google (Chromebooks, Nexus Tablets, Android phones) and Apple (Macs, iPods/iPads). I wouldn't say Google is that far behind but Google's entire mentality is different. They're a web services business first (and a business that makes money from ad revenue) so everything about the Google "experience" involves connecting to the web and isn't really a whole lot different on a chromebook vs Chrome on a Mac vs Chrome on a PC. The nice thing about Google is that a quick sign in from any terminal anywhere and you have your stuff, synced near instantly.
I can't tell you how amazing it is to fiddle with my older Samsung Chromebook, test out features, set things up the way I want, and then open my newer HP 14 chromebook and get all the settings automatically synced up. The device becomes meaningless (or a means to an end).
I think competition between these guys is going to be great for all of us because whatever platform becomes your favorite (I'm in the midst of moving completely to iOS myself. I can't help it. The hardware is sexy.), we're going to get a lot of new and great features from each platform trying to one-up the other. The market at large probably has different enough tastes that both will be able to survive with a relatively large pool of loyalists as well.
Really, I see Microsoft as the also-ran. They're the ones that ought to be worried, though I do like some of the stuff they have done with Windows phone and Nokia.