If you read the Rctek posts (
http://www.rctek.com/phpBB/viewtopic.php?t=5612 ) about the Magneto Diff, you will note that the newest versions also comes standard, with 2 friction plates, which was former one of Oddifieds mods to the Diff..
If I ever wants a Locking diff again, then I will go for the Oddified one, but the Elcon one runs FINE for my driving.
I used to run a std. FG Diff, that I had converted to a 2 plate self locking diff, but drivability on loose surfaces was AWFUL.