The nylon will outperform the leather in most every aspect, but I expect you know that already. The snap and the velcro can compete well enough, but snaps do wear out and velcro does get clogged.

I debated this myself, and decided to ask my wife for the nylon sheath to replace my leather one for my wave. The leather looks less "urban", so that was part of the reason, but it also wears faster and doesn't withstand water so well. Plus it seems to me that the nylon just wears "easier" on my belt - hard to explain, but it doesn't feel like such a brick when it's on. Plus, if I put my belt clip attachment on, the wave doesn't fit well into the leather, but does just fine in the nylon. The nylon sheath also has just enough room on the sides to clip a thin pen or one of the Coast flashlights I've mentioned elsewhere (under a quarter inch thick tube).

Here's the kicker... get the leather one if you are so inclined, and pick up the spare nylon sheath for the $6 or vice versa if it doesn't turn out. If you wear other gear and you want it to match, then that might affect your decision as well.

Either way, a ballistic nylon sheath will outlast the leather, but if you treat the latter right, don't get it wet, it will do just fine too. They do smell if they get wet though.. <img src="/images/graemlins/smile.gif" alt="" /> It's not like it's going to break the bank to change your mind on this one, but I went with the nylon replacement after wearing the leather for a year.

Just FYI, I also bought one of the new Leatherman knives (very nice) and the sheaths are different in styling from the wave - with gray and black instead of all black. I haven't seen the titanium LM, so maybe it's to match that style sheath? I'm thinking of getting another wave pouch so my set matches - I prefer the plain black style, myself.