I have now OSZ Vertex 2, a 240 GB SSD drive, installed into my main workhorse, the Sony Vaio Z31WN, and I have to say I am impressed. The laptop feels totally different, much faster, more responsive — a system shutdown that could take minutes (or never complete totally) happens now in a few seconds. Much of the stability, speed and better user experience is related to the OS change: along with the new hard drive, also the old Vista was replaced with Windows 7, 64 bit ultimate/enterprise edition. But the step into solid state disk is nevertheless a major one. There is new life in the old machine. I have not yet tested the new setup completely, and there were areas like getting the 3G Gobi drivers to work with my Finnish operator’s network that were rather difficult (I ended up using the “WebToGo OneClick Internet” utility). And getting the old hard drive replaced with the new one is very difficult without professional help due to the complex Vaio Z series internals, so I cannot recommend this is as a DIY project. But having an SSD as the main memory device is clearly the way of the future for mobile computing.
frans goes blog 
Oh yes, and many thanks for Mig for handling the upgrade – almost at the Christmas Eve, of all times of year!
I think the duration of battery is not so greatly enhanced than the system speed/performance otherwise. Most of the electricity are probably consumed by the LCD screen and the processor, so the lower power consumption of SSD is not so crucial factor, but the practical use time of my standard battery is probably almost doubled now (c. 3 hours > 5 hours), which is not so bad.