Bryan I can report on the P450 with good authority as I recently bought one to go with its mate (the C275) which I also bought early this spring.
I had been searching for the past 4 years, looking for a combo to better my beloved Luxman Ultimate components when the amp failed unrepairably in '97. I'd tried a number of other lines: Krell, Classe, Conrad Johnson, Ayre, McCormack, Marsh, Perreaux, Sonic Frontiers, Golden Tube; some were more or less satisfying than others, but all left something lacking musically despite the minimalist design approach. I even considered Luxman again but their "product support" scared me away. Looking toward other full-featured products I then discovered the Accuphase line, & bought the preamp sound-unheard. Wow: now I was finally getting somewhere! Resolution & musicality all in one package with every feature that I could ever hope to use. Hopelessly addicted now, I had to have the C275's mate & again bought sound unheard. Wham; this is THE one! Talk about involving!
You've just got to get ahold of one of these amps. Resolution & warm musicality are offered within a very neutral sounding envelope, as Kelly also attests, and it's still affordable. If you have deep enough pockets then I would definitely consider an audition of the A50, which Kelly really likes with his Avalon's & a Tara The One AC cord. My own lineup includes much of Synergistic's better cabling with the active shielding center, and MIT's better speaker cables driving a pair of vintage Belle Klipsch. This 200 watts per channel driving horns is so incredibly dynamic (incredibly crazy too I'm told: hee hee) with an HDCD or an analog front end either way it's just amazing. Another charactaristic of the sound is "completely in control" so much moreso than anything else I've tried. WAY recommended!