ComputerWorld has a roundup of several solid state drives and hard disk drives:
Having no moving parts is, naturally, important. There's no platter rotation or read/write head motion so SSDs -- in theory -- should use less power than equivalent mechanical hard drives. They should also (again, in theory) be faster than a mechanical hard drive at just about anything. Working off an electrical grid, there's no time wasted positioning the read/write head and then waiting for it to settle down and start doing its thing. SSDs just do it. (That's a bit of an oversimplification, but it's fair.)
So have you ever wondered if it's really worth it to plunk down the extra $1,300 for an SSD-equipped MacBook Air? Or have you been tempted to swap the current mechanical hard drive out of your portable and slide one of these high tech bad boys inside? I did.
Check it out over here. The reporter concludes SSDs have yet to live up to their true potential, their performance isn't stellar and they still cost way too much.