I'm not sure why everyone thinks titanium line will damage the rod. It's just a thin, light wire. Anyone who raises this as a concern hasn't tried one. If you tried one, you'd see it's not heavy and sharp enough to cut through graphite merely by casting. And, if your line is hitting the rod that much, there is probably something seriously wrong with your casting technique! In fact, I don't think you could even cut through a blank with it if you made a concerted effort and intentionally ran it back and forth over the blank like a saw.

Tatsurou Okaniwa (owner of tenkara.com) developed titanium lines over 10 years ago and he uses them exclusively. As one of the most experienced tenkara anglers in the world, I highly doubt he would continue using them for so long if they were cutting his rods in half.

These lines have their application. Just as floating lines, nylon lines, fluorocarbon lines, and furled lines do. No one line will satisfy everyone's need in every situation. This is a specialty line and does what it is supposed to do well.