Originally Posted by Mountain Vision 
Hmm, I have used PPL for many images, and I can tell you this, the conversions were better than ACR.
I agree. I've tried several times to use ACR, I even bought Bruce Fraser's book, and always came back to PPL.
It's possible ACR works better for other camera brands, although I've seen similar discussions by Nikon users and many prefer the Nikon software even though it's admittedly kludgy.
As for the whole 16-bit thing, a lot of people (including Fraser) point to the histogram in PS to "prove" how "destructive" various processing methods are. Histograms are useful to a point, but they're programs like any other and a lot of their value depends on what's going on in the calculations. It's my understanding that some features of PS haven't changed since being introduced - new versions introduce new features but aren't a complete rewrite.
If it makes you feel better to process in 16 bit, by all means do so. I think the real test of processing is in looking at the output with an educated eye and not worrying so much about theoretical numbers. If you print an 8 bit file and a 16 bit file and can't see a difference, the difference isn't enough to worry about.