As far as I'm concerned not using SSD is silly. We've been waiting to replace the slow unreliable dinosaur HDD's for decades now.
Even the cheap SSD's are fast, get one now and then as the cash becomes available and add a 2nd, 3rd and 4th in raid0 for insane speeds.
I swapped out the 7200rpm drive in the gf's dell studio xps 16 with an intel x25m 80gb without her knowing. That night she said the internet was running really fast. Couple days later she asked me if I did anything to her computer cause it was running "fast". This coming from a girl who is oblivious to anything other than clothes and shoes. Hell, I just put winter tires on her SUV and she didn't notice (In fairness it was on a second set of identical wheels but still..)
HDD's still have their place.. Adding 2TB to the home server for $100 a pop feels really good.
EDIT.. forgot, when selecting a SSD go for read speeds and $ per GB, the only time you will notice write speeds is when you're extracting an iso or copying very large files, and even then the difference from drive to drive will only be a matter of seconds to tens of seconds.