I've got one of the Linksys units... the one without the built-in hub. It works well, most of the time, but occasionally hangs. Mostly if I haven't used it in a while, but sometimes when I'm actually using it. Traffic just stops going through it, and it won't answer pings. Rebooting it (unplug, then plug) solves the problem.

I do leave all my PCs on 24/7 so it could just be that it wasn't designed to be running for an extended period of time.

Sometimes it'll hang twice in an hour, and sometimes it'll run for weeks before hanging. It's not too terribly annoying, since the fix is easy, so I never bugged tech support about it. YMMV.