I too had qualms before I ordered mine (at that time they were on the refurb store) but was calmed with the fact, like everyone has said, most people here come with problems, the majority are fine. My CD 2.0 is FABULOUS. Doesn't get anything but warm to the touch, the fans barely are audible, they finally went on when I was playin a dvd while usin photoshop, dreamweaver, preview, printing app, ichat, adium, mail and surfing the web lol!
I find my machine just great, and the screen is terrific too. No icky grainy issues or anything of that matter.
Since you said your listing was on craigslist you will get a chance to see it and try it out first, so that's good as you can see any main problems that may jump out at you, and feel how hot it was getting. Mine runs cooler then most of the c2ds i've felt and I haven't had any problems. My bf has a cd 2.16 and his runs just great (we had to replace the battery as it was DOA but that was part of the recall before he got it [new in box on clearance] so it was replaced quickly... but once again you can check all this out)
Anyway.. a CD is a good cheap option to get a really powerful machine that will still last you for a whiel without having to shell out for a newer c2d. All versions come with their share of problems.. chances are though you will find yourself with a perfectly fine machine. I would check however if you could still add applecare to it (if it's still in it's first year, it should be) and check all that stuff out to make sure.
GOOD LUCK!