The leather one is a nice sturdy little sheath with a button closure. I've carried one for long time, and still do from time to time. Now the plastic one is another story. It breaks quite easily. Only took me a couple of days to catch it a bit hard on something and it was done. One of my friends had the same experience with it.
I've broken three of the plastic ones in a short period of time and am on my second leather one. I EDC a Cs4 so the sheath gets worn every day. The elastic sides on the leather sheaths give up after a while.After carrying the LM for over three years I'm about to give up on it and switch to a Spirit...as soon as I make my own sheath for it.