I was still considering getting a hard drive, until someone at my office put a 160GB 6th gen IPOD Classic up for sale for $200. Refurbished ones at Apple are still $250, new ones a lot more. I had ZERO desire for an IPOD until I got this headunit, just didn't see the point for my needs.
Anyway, he let me borrow it for a couple of days before I bought it, and I must say if you are considering buying a hard drive instead of an IPOD you are IMHO making the wrong choice (as I was). The IPOD controls are SWEET, voice recognition works fine for me....it's VERY cool. I currently have 130GB of data, about 18,000 songs. Original sync took about 10-12 minutes on the Pioneer, but after turning off the VR Catalog it only takes and extra 10 seconds or so to boot if IPOD is the source, no difference if I am on FM/XM/etc.
Pretty much all my music is on here now, so I have just run the wires into the glovebox and plugged it in never to be removed (unless I add more music later, etc).
Highly recommended if you can find one.