The HPX-500 is the big brother to the stellar HVX-200. There’s a nice review up from a UK site. IT certainly seems to have a lot of benefits, particularly if your workflow can take advantage of the benefits of P2 without the disadvantages. It’s a very affordable step up for the HVX (street price is around $13,000) which makes the cons (lowish-res CCDs, limited manual tweaking) seem less problematic.