Here is what I can tell you about the 993, from personal experience. It's the best driving Porsche I've ever driven, and I've driven a lot. It leaves you wanting nothing, unlike the 911's that came before and the abysmal failure that was the 996. A friend who works for Porsche says the joke there is that the 996 was the car the accountants designed.
As far as values leveling off or dropping, yes, they probably are, but only because the 993 was becoming very over-valued, something had to give. The good news is if you couldn't find one or afford one two years ago, now is your chance. The good news for me, is I can still honestly say I only paid $5000 for mine, about 3 years ago. Of course, I try not to count what it's cost me since that day, did I mention it's back in the shop...
---Adam
