Simon, if I understand your post correctly, you have bought a P-4200 power amp. If that is indeed the case, congratulations!
Dave and Simon, the C-28xx pre-amps are actually significantly better than the C-24xx. The C-28xx models stand out as being much more dynamic and at the same time sounding much more relaxed - they have a much better control over all aspects of music. Personally, I would rather go for a 2nd hand (or demo or ex-demo) model from the C-28xx line than a new C-24xx model.
I've tested rather extensively many Accuphase integrated and in the end I have ended up with the E-550 class A integrated, then I moved to A-45 & C-2410 combo and then to a A-65 & C-2810 combo. The differences between the E-550 and A-45 & C-2410 was solid but probably not worth the price difference (especially in my case as I did not needed the additional power). On the other hand, the difference between the A-45 and A-65 have huge, as so was also the difference between the C-2410 and the C-2810. Now I am contemplating to get a C-3800 pre, I have actually made a down payment but I am not yet 100% sure that I will go through with it - I am a bit afraid the C-3800 will be replaced soon. :(