For bare basics? Second hand is best
Think of it this way, basic word processing's been done since the first personal computers were marketted. You'll pay way less, the idiosyncracies of your machine will be known—to others, ("buy what you friend's know") even if they're "yours to discover". Used machines often come with SW installed—though we know they shouldn't—and the appropriate …for Dummies books are remaindered, or available at the library. Do we really need to be cutting edge for just the basics?
As for reliability: I'm on my third Mac Powerbook, my first is still being used for "just the basics" by someone else. Number 2's been a 'parts car' for #1, but it'll be kitchen e-mail with a new HD. Number 3 is speaking to you now. I've dropped 'em, froze 'em, left 'em in the rain, explored their insides, they've never needed a service person. The Jellybean clamshell iBooks are even more rugged. My colleague paid five times what I did (less that a K three yrs ago, $200 currently) for a new IBM ThinkPad and had to spend even more money to network at all, and way less easily than me. And he crashes and freezes more often.
BTW CinemaFace is dead on about batteries, and if AC-free matters to you, you need to beware the "NiCad battery memory effect". Most used computer batteries suffer from it if they're NiCad, and you'll get way, way less than 3hrs use. But I live in a world w/ AC everywhere and I just plug in. Apart from the battery-biz, trailing edge is the way to go.