I'll never have 4 subs, 2 is the most I can get in this room (or need).

I'm actually quite pleased with the PC tuned, Audyssey + Editor app with my 4700H, if I thought I needed better I'd spend $200 for the Mult-X upgrade app.
To get a Dirac update, I need to buy at least a new X4800H ($2700) + at least another $700 for a full boat Dirac upgrade package. God only knows how much Dirac is gonna hose you to then upgrade to ART when it does finally come. Sorry partner,, but IMHO there's no way in hell I'd get $3400 or more improvement to swing over to Dirac, it's a good DRC app but it doesn't part the waters over everything else.