openmedia: Do you have the single battery or dual battery one? I tried the single, but the plastic cutting blades are useless.

The 36V line-trimmer model, I believe the single-battery one is the plastic-blade one that Gymjunnky was so enthusiastic about in the link I posted previously.  Haven't had any problems with it in about three years of use, and I'm only just getting to the end of the first spool it came with.

One thing with line trimmers is if you're using them as excavators, e.g. to dig into the dirt along the side of a path to get the weeds there, or even running it down the edge of a concrete mowing strip, you're going to go through a lot of line very quickly.  The likely reason why I'm still on the original line is that I use the trimmer shield as a guide to where the line stops, so 99% of the time only hitting grass or weeds with it, not dirt or concrete.