No need to upgrade for me either.
It is because I bought full PS6 just before 7 came out that I now use 7, just because I got it for free.
IMO, there wasn't a real need to upgrade to 7 at all. The dinosaur just got a tad bigger. And the books I have are all for PS6.
16 bit? I can import in 16bit LAB from my scanner (having done nearly all corrections in the scansoft), and in 7 I can use Levels and Curves.
The rest can be handy, but I wouldn't spend that amount of money on a plug in that could do the same things either.
And as far as the suite is concerned: I am told that in the future, you'll need to upgrade the suite itself, not the individual progs separately.
MsOZ: thanks for mentioning that secret thingie. Always had the feeling something was wrong rom the first moment...