Not to hit a sensitive subject, but I prefer the Deregulator mod better because I like to lay my thumb along the blade, and the upper guard prevents me from holding the knife that way. That's why I passed on the Regulator LE, although otherwise it has a wonderful fighter balance and is nice and shiny.

I use a lanyard with the khukri I chop with, but it isn't an around-the-wrist sort of arrangement. I drilled a hole in the handle, and run a snug loop across the bottom and back of my hand and around my thumb. It takes some adjustment to get sized right, but then helps retain the knife in my hand. As Vic has noted, you're a lot better off just letting a knife fly once it slips out of your hand -- be careful to keep bystanders out of the way when you're chopping, but otherwise, just let it go. Some of the same rules apply when chopping with a big blade as with an axe -- accidents tend to happen if you let yourself get too tired and when you don't have good visibility.

NOTE: Text edited to correct my lanyard use description.