I second everything Docent said. I will never build another PC without an SSD in it.
I've actually convinced my office to buy SSDs for all our developers' machines instead of upgrading to complete new machines this last year, and sticking SSDs in our 3-year-old machines gave us a better performance boost than entirely new machines would've.
It does require fairly specific storage habits, but you get used to that. Most of it comes in setup, and after that it becomes second nature. First thing I do after installing Windows 7 is re-point all the standard media folders (Downloads, Music, Videos, etc.) to my secondary HDD so that they don't clutter my SSD. Once you get your media to live comfortably on your HDD, and nothing but pure application data on the SSD, it's a glorious thing. I can't even remember what it's like to click on an application and have to sit there waiting for it to finish loading.
There IS a down-side to SSDs though!!! Be warned!! Some games these days are designed with loading screens that have useful tips and hints on them. For example, Skyrim. As you're loading a game or changing zones on Skyrim, the game displays useful helps/hints about gameplay. You will never see those with an SSD. It loads too fast. :\
Edited, May 7th 2012 8:26am by Pergatory