I hit the sometimes catagory because I run into situations that aren't really what I would call trims but more of a semi - removal of a tree. Removal of a large limbs or an entire lead from over a house, garage. wires.
In this case I'll get up the tree without the spurs then have them sent up to me and put them on in the tree and use them on the parts to be removed. I only do this if there is a lot of climbing involved or if the angle is almost vertical like they are in these soft maple trees we have here, where using spurs is faster than trying to advance a line, or trying to get foot and hand holds here and there.
If the poll had defined "trims" meaning just crown thinning and cleaning then I would have hit the never catagory.
I don't hold to Rocky's opinion that you are not a real climber to "get up a tree" if safety is more of a concern, than trying to prove a point by not using spurs. Even though using spurs is a bad practice, if it comes down to me risking injury or the tree suffering from a few spur marks, the tree is going to lose.
I had a three leader Black Loucust this summer that got mangled in a wind storm. The two biggest leads { the best ones ) failed at mid point and was split lengthwise, approx. 5 ft., I could put my fist through these splits. The wind left the smaller weakest lead standing.
Even though this remaining lead was a " living tree " that was not going to be removed and spurs would have been a taboo to use to "get up it", I still spurred it and glad I did . About 3/4s of the way up I found a defect that could have failed if I had been body thrusting or footlocking with my full weight on my chosen TIP, had I been successful in getting a rope through it from the ground.
After spurring up, then down, I had to contend with the split leads . In addition to the bad practice of spurring a live tree, I had to break the rule of being tied in twice while making a chain saw cut. There was no way I was going to be harnessed with a lanyard to these split sections of wood should they have come apart while sawing them.
I only put this up as an example that rules and principals can't all ways be followed when it is a matter of saftety when doing tree work. If a tree has to suffer some type of indignity from the dig of a spur because of a safety concern, better the tree to suffer than me.