This is a bit of a tangent, but related.
If you want to get the most out of an ssd, one thing I think you can do is separate an ssd into two partitions. If you have a 120 gb ssd have one partition at 100 gigs and the other at 20. Install the OS (and anything you need to be extra fast) onto the boot (100gig) partition. Then use the other 20 gigs as a cache for whatever hard disk you have installed (but make sure to use "enhanced" rather than "maximized", so that the data is safe)