The height of those eucs are incredible. The tree next to the one he's topping out disappears out of the picture. makes the tallest Tulip tree around here look like childs play. What a ride!!!!
I'll usually always try to use a block whenever possible. I feel like it depends on the ground guy also...If they are able to let it fall and slow it down, go bigger. If I'm unsure I always will climb up and go smaller. This part of the job you have to have complete faith in your crew.