Last year I bought a SanDisk 480GB SSD for my 2009 MacPro, cloned my old HD with 10.6.8 over to it then updated it to 10.8 so that my orphaned software could still be used as needed. My older drive still has the OS installed and I boot to it perhaps once a month to use older software no longer compatible in addition to using this drive for temporary image storage as I download, screen and edit the photos before I archive and back-up my photos. No real complaints about the SanDisk. It boots faster and programs load quickly. So far so good after 18 months of use.
IMO, any of current faster SSDs will give you better performance than a spinning platter drive. I don't think you can really do wrong with adding an SSD to your system and squeeze some more performance out of your system.
From my experience OWC does stand behind its products and their prices are competitive.
With the price of many 480-512GB drives in the 200-300 range, and smaller capacity drives even cheaper, they are even more affordable now, an inexpensive upgrade along with maxing out the RAM to get more from older systems.