I wouldn't call myself an expert arborist, but I cut the firewood that provides all my heat in the winter. The safety features (mainly the goofy guard they put on the end of the bar) are good if you're a homeowner cutting some shrubs a couple times a year, but you have to take that off to drop a tree or cut pieces wider than your bar, so they aren't practical for serious work.

Fortunately, a chainsaw isn't a very dangerous tool, since it stops as soon as you release the trigger. The danger in dropping trees is from the tree itself: having one fall the wrong way or crack loose at the base before you expect it. I don't drop anything large when I'm working by myself, for that reason. I've been mildly injured by some surprisingly small trees, when something happened to bounce where I wasn't expecting.

If you’re regularly cutting pieces of wood wider than your bar, for god’s sake invest in a bigger saw. It will serve you better in many ways, safety included.