I have a 2000 996. It's been my daily driver since I bought it about five years ago. It had 37,000 miles on it at the time - it now has 122,000 miles and counting.
It has been a supremely reliable and well built car. It goes through rear tires about every 12,000 to 18,000 miles, depending on the brand of tire (and always wears them on the inner edge first due to the negative camber Porsche sets up for the rear suspension), it had one alternator replacement about four years ago, I replaced the Air/Oil Separator (AOS) myself last winter (saved money, but it was a tough job), and I finally got around to having my Porsche mechanic/buddy replace my clutch, so while he was "in there", I had him replace the Rear Main Seal (RMS) and the potentially disastrous stock Intermediate Shaft Bearing and flange (IMS) for the re-engineered and essentially bomb-proof LN Engineering version. That was the best upgrade to the car so far and has basically eliminated the potential for an engine destroying IMS failure - which tends to be on 996, 997, Boxster, and Cayman owners' minds. If I were you, I'd replace the clutch as soon as possible, and then have the upgraded IMS and flange replaced with LN's version. You will gain very inexpensive peace of mind. These engines are actually known to be very robust otherwise.