I haven't done a whole lot of cutting lately. Plunge cuts are used a lot in ash. It helps to prevent any splitting of the butt. It is probably safer, since you won't get a barber chair.
I used to use plunge cuts for bucking logs as well. It prevented logs from splitting and you didn't pinch your saw. You have to be careful, as pointed out above.
As for damage to a bar, the tips are often replaceable. I don't recall doing any extra damage using plunge cuts. Besides, the cost of the bar is much less then the cost of a log that goes from veneer to a #1 or less.