Wow..I had never seen the huge wood eater before...cool.
I first used a chain saw when drafted and based at a Conservation camp in CA. We cleared a 1/3 mile fire break above Oakland...huge Eucalyptus trees. I loved it, watching them fall was a thrill. I learned to use telephone pole spikes to shimmy up a tree and top it, using a climbing belt and small chain saw. I did that for about 6 months when I was 19, with only a few injuries, nothing serious.
In 1986 I moved into an Intentional Community on 23 acres mostly forested. We used a stove to heat the house with, and we would use about 4 chords a season. We used Husqvarna saws. Sharpining by hand is ok, even with a good guide, but taking them in to have them sharpened works better, but costs out the ying yang. I have gotten to old to do it anymore. Another "comrade" does it now.