I had a computer that was about 5 years old (Intel E6300, 2 GB RAM, Win 7 x64) running business applications. I added an Intel SSD 320 series 120 GB drive. This made things feel a little quicker but was not a night and day difference. I recently upgraded the computer to (Xeon E31225, 8 GB RAM, Win 7 x64) and moved over the SSD and everything is lighting fast.
The computer is a system, which is only as fast as it's weakest link. In general if you access a bunch of small files, you will see an improvement, if you access a few large files you may not see much improvement.
Thanks for a good example of what to expect with this type of technology. Too many fanbois expect latest and greatest from incremental advances. Benchmarks on these don't really jive with real world experiences as most of the time computers are usually doing nothing much but waiting.
Finally prices are getting to my price range I had set for myself 2 years ago ($1 per GB). I must admit, I wasn't expecting such low prices from Intel, thats good news indeed. I may finally go with an SSD by Christmas.