Well, let me rephrase- Linux is as stable as you want it to be. If you want an ideal linux laptop experience, you need to do the research and get a model made with linux in mind. Otherwise, you're just rolling the dice.

That being said, I only use Linux for server-side work, and I can easily say that it is every bit as stable as any other server OS I've used, and has been for a very long time. There are plenty of weedy areas to play in if you want to, of course. But if your goal is It Just Works, you can do that, too. Perhaps most importantly, you can do it easily, with just a little foresight during the spec stage of planning your project.