You definitely see faster load times but for the price you pay for and how much storage it contains its almost not worth it. SSD is new technology and it will be expensive to buy at first. Personally I wait a year or two (Probably when PS4 comes out) to buy one.
Better off having either a hybrid model or a HDD with 7,400RPM.
There are a few articles online, and several users have upgraded to SSD if you try the forum search.
Certain tasks and games load faster, but I decided it was more cost effective to get a Seagate Momentus XT instead. Most games aren't bottlenecked by the hard drive in the first place, so they won't see much of a benefit if any.
The bottleneck is the PS3 SATA interface, so you can safely go with the cheapest and slowest SSD you can find. Make sure you check the manufacturer's website for firmware updates and upload them to your new drive on a PC before installing it into the PS3.