Since the thread was revived by the Ford mower driving line salesman from China, I'll chip in anyhow.
I ran a lot of Echo Crossfire line, but I agree that it was too soft, especially around fencing, concrete, and brick. I am using Husqvarna Titanium Force line now after trying some on another machine. I like it, lasts a lot longer for me than the Crossfire did. I paid ~$40 for a spool at the local small guy.
When my spool of Titanium Force is gone, I am going to move to the Co-Extruded dual polymer XP Force Husky string- my neighbor has some, and it lasts longer still. Great line.