For some of the battery power non-believers. I've always weed-whacked my 7 acres (1 acre yard, but then fence lines around barns etc.) with a commercial model Stihl or Husqvarna string trimmer. Last year I had some issues with my latest Stihl and on a whim I bought an open box/Demo Milwaukee string trimmer at my local Northern Tool. I'll never go back to a gas powered string trimmer. It starts immediately when I press the trigger (has 2 speeds), is quiet enough that I don't need earplugs, lighter than a gas trimmer and it will do my 1-acre yard with one battery (If I haven't let it grow too tall). Otherwise, I have plenty of other Milwaukee batteries anyways. It also holds a heck of a lot of string and is super easy to spool it.
There's something dramatically different with the newer gas powered equipment that makes them finicky as hell and less reliable to start and stay in tune. I've always used quality fuel and premium 2-stroke oil, but today's engines aren't the same as yesteryears. I don't know if the drop in reliability is emissions or fuel economy related, but they've changed.
I will definitely be retiring my Stihl pole saw next and replacing it with a Milwaukee pole saw.
