I prefer the LMF rods. They're easy to spark and last a long time. You may have to be a little more selective about what you use for tinder, but I carry a small pill bottle full of pjcb's anyhow, so if it's a real emergency I'm set. The greater controllability of the LMF's vs. softer rods means that it's easier to hit your tinder. The biggest, longest-burning globs don't do you any good if they land in the snow instead of your tinder.
Edit: Rick Marchand has an excellent video on a way to produce great sparks off of an LMF rod without "hour-glassing" the rod over time and having it break. Since seeing his video on it I've been using the technique exclusively with good results. Use the END of your striker, hold the rod with your left hand and the striker in your right, with BOTH of your thumbs on the end of the striker. You then "snap" your hands as if snapping a twig with your thumbs. The striker will launch a nice, large spark, and you'll only scrape the very first cm or so of the end of the rod. This DRASTICALLY reduces wear.