I've owned many brands of hard drives over the years. About a decade ago, I and many of my friends thought of Western Digital drives to be low-quality, failure-prone products. It seems that today the exact opposite is true.
Recently I've owned Seagate, Maxtor and IBM drives, and have had all three of them suffer mechanical failures within a year. Now this drive is my second WD drive, and thus far all is perfect, on BOTH WD drives. I think it's safe to say what company I'll be choosing from on future hard drive purchases.
Obviously this drive is faster than your standard drives, hence it's name Raptor, and it's 10K RPM specification. What does that mean for the average user? Well, for me, it means I'll copy files and load games and things like that faster. Great for the impatient types like myself.
Obviously though, it is only 150GB's, and for a price that you could get other more standard speed drives with probably twice or more the capacity. If you can live with the standard speeds, then just buy another drive and get way more capacity. If you want to be faster than the next guy though, here's one of your best options.