I used to use FCP 3 but for the past few years have been using Avid through my work. The beauty of FCP is the ease in which I've picked it up again. It's very instinctive. Of course, things have moved on and now we have FCS 2, and boy is it a powerful beast. I'm only scratching the surface of Color, Motion, Soundtrack and DVD Studio Pro but have been impressed by it's capabilities. There's plenty to keep me occupied during those longer winter evenings - girlfriend permitting.
Yes you will have to invest in a decent Mac, and these don't come cheap. However, the initial outlay is nothing compared to how much you can pay for some editing hardware with software; and these don't necessarily come with all the bells and whistles that FCS 2 comes with.
A word of advice to avoid frustration. A problem with FCP 6 is that it can't see the Motion templates when using Leopard. You will need to download the latest versions of FCP and Motion. The latest versions are currently FCP 6.0.4 and Motion 3.0.2. This won't cost you anything.