Well, it's up to you, but keep in mind that even though you buy the SATA2 hard drive your transfer rates are still going to be decided by the mechanical portions of the drive, which will never change. If one has a larger cache, then it is safe to assume it will perform better in the burst rate arena. However, the STR will still rely on the mechanical parts, which are very slow compared to the bus speeds which seem to be ever increasing, without any innovation in the mechanical arena, except for denser platters...