Yes, it would still be worth it IMO. Much of your day to day usage is accessing many, random small files, and an SSD is much faster at doing that, even over a SATA I interface. There are not many SATA II SSDs around any longer, and most I have seen cost more than a new SATA III drive. SATA is backwards compatible, so I would just get an inexpensive SATA III that is reliable like the Samsung 840 mentioned above.