The Reevoo dev team recently upgraded all our desktops to SSDs. I forget the model, but they are those ones that don't need trim support, or some shit like that.
Keep on reading though, I made graphs and everything.
What I'm trying to say is that they make a huge difference to the speed and pleasure of development work.
It makes switching back and forth between Textmate and Chrome instant, and let's face it, that is what I do for a living.
The point is summed up nicely by this graph:
… and if that's not enough evidence for you, how about this graph?
This leads me neatly back to velociraptors. Velociraptors are the only natural predator of developers. Every minute you spend waiting for stuff to happen and breaking your flow they are slowly creeping up on you.
Now go and buy a fucking SSD before the raptor's catch you and eat your fucking face off.