I wouldn't consider any guitar "investment" anything -- I buy the ones that are pretty to me because it pleases me to own them and motivates me to play them more. The only ones I've seen become more valuable ("investment") are the limited runs.
However, I will say that I think PRS is in a shining year right now and when people look back on this particular era of their guitar-making, it will be considered one of the better years. So if life is fair, it should retain its value more than previous years.