When you get down to it:
Pro:
-Faster (read better than HDD, write the same or better but super low latency)
-more reliable (as moody said, no moving parts)
-use less power
-zero noise
Cons:
-cost/GB much higher. The largest drives I have seen are 256GB. I think they have 512GB drives for $2 grand now. Compare to 250GB HDDs pretty much phased out in desktops and on their way out in laptops.
So really it comes down to do you want the space or the speed and reliability?
$60 for a 250GB 2.5" HDD
$800 for a 256 corsair SSD
If you have the money, there are no cons to an SSD. There used to be firmware issues but I believe they are all gone now.