That is a fact! I went with the Giraud over the Henderson because the Giraud trims off the shoulder and not the entire case length, which gives the same neck length on each piece of brass. Which, based off my own logic, would produce a more uniform surface contact with the bullet than trimming to a certain length.Whidden adjustable lock rings should be standard equipment on a giraud. They are awesome on there.
A cheaper option is the Lyman trimmer which uses the same concept.
The Henderson is a great trimmer and they are really nice people to talk to. I am not knocking their product, but I like the Giraud trim method.
Using a K&M case holder/power adapter handle will save your hands a lot of fatigue.