I'd go with the 500GB drive... much more practical.
SSD drives are nice, but I wouldn't do anything lower than 128GB... 80GB would be insane!! my iTunes would fill up like 70% of that.
Until a 256 drive is less than $250 they just aren't worth the speed difference.... once they are close to being $1 per GB I would consider them FOR SURE.. but wayyyyyyy too much of a luxury item still.
If only express card SSD were actually fast.. I was going to buy a 48GB wintec SSD drive for my express card slot, but ive heard it's a bad idea to install OSX on there, because as soon as you computer sleeps express card drive shuts off.. and helllo corruption city.
I'd still consider one to just store a bunch of videos and some music... but since it's basically just as fast as a .7200 rpm drive, probably not worth the $150 dollar price tag. I might as well just upgrade my 320Gb to a 640gb Drive, and throw the 320 in a case, or in my PS3.
Anyone have any luck with a SSD in the express card slot?