OCZ Vertex 3.20 240GB Solid State Drive Review @ OCIA.net
 

The key difference this time around, however, is the selection of MLC NAND. As the name indicates, the Vertex 3.20 uses 20nm MLC NAND compared to the larger 25nm / 34nm variants found on the original Vertex 3. It's part of a market-wide push for smaller flash across the board. That aside, everything else under the hood remains virtually the same although LSI now owns SandForce.

http://www.ocia.net/reviews/vertex320/page1.shtml