So intitially I went from an 8x 15k 2.5" Savvio 15k.1 setup in raid 5 on an Adaptec 5805 to a single Vertex. I jotted down my thoughts just after switching:
http://www.servethehome.com/ocz-vertex-v-sas-15k-rpm-raid-5/
At the time, I also had a 3x 300GB 15k Raid 5 as a slower, second-tier storage (before the 7200 rpm SATA tier):
http://www.servethehome.com/3x-seagate-atlas-15k5-raid-5-adaptec-3085/
Now: I have 2x 120GB Vertex drives in raid 0:
http://www.servethehome.com/ocz-vertex-120gb-updated-raid-0-benchmarks-intel-rst/
The different kind of fast would be accurate from that Savvio setup to the Vertex setup. The new Raid 0 vertex setup would probably be alltogether better, but coming from a single SSD, there really isn't any noticible performance with Raid 0. (Yes, I keep all files on a backed-up Raid 6 server so I'm not concerned about raid 0 with nightly backups as I don't install programs that often).
Also, I bought a Vertex LE 100GB and returned it after a few days. I couldn't tell a real-world performance benefit over the original Vertex and it has a huge price premium. Given, benchmarks are great and all, but I don't benchmark for a living. X25-M v. Indilinx drives, really not a huge difference either, at least compared to 7200rpm drive to either SSD.
Just some thoughts.