The video specifically shows that the Giraud is NOT more accurate than the Henderson - all the Henderson-trimmed brass were at +0/-1 thousandths, and the Giraud was less consistent, with one coming in at 4 thousandths off. I've validated the Henderson consistency on 100 cases where the SD on overall length was .000577" - it is exceedingly accurate due to the hard stop method on the Henderson. He mentions this in the video - the amount of force you put on the case on the Giraud changes the trim length. He caveats that the measurement method for the Giraud-trimmed cases is slightly less accurate, but that in itself is an issue. Why wouldn't you measure full length on both?
Because:
The big question is what is more important - indexing off the shoulder like the Giraud, or indexing off full length like the Henderson? Indexing off the shoulder (Giraud) helps ensure the neck length is more consistent. Indexing off the base helps ensure the overall length is more consistent (e.g. - where the case mouth is positioned in at the end of the chamber). Consistent neck length helps ensure your bearing/frictional force holding the bullet in is more consistent, while overall length allows you better trim to chamber length and minimize carbon build up (leads to carbon rings).
At the end of the day, I made the assessment that being, call it, .001" or so more accurate at the shoulder was lost in the massive amount of other variability that enters into the bearing and friction forces that hold the bullet in place. That .001 adds low double-digit basis points of variability, while other factors could add a thousand basis points or more.
On the timing aspect, in the video he says he is essentially brand new with the Henderson and he has 20 years experience using the Giraud. This shows when he fumbles with a few cases with the Henderson (and is really fast with the Giraud). Additionally, he has one case that the neck wasn't expanded on which cost him a couple seconds. I'll give you that the Giraud is faster, but probably more in the 25-35% range, not the 1.5x exhibited in the video.
One last thing to bring up is how does each trimmer impact the seating force? This is arguably the most important aspect.
Here are screen grabs from the video showing the AMP Press plots:
View attachment 8368518
View attachment 8368519
Unfortunately, the Y axis units are cut off in the video, but it's clear that the Henderson offers a more consistent seating force. If you just measure the magnitude (in pixels) its 155 for the Henderson vs 178 for the Giraud. That's 15% more consistency over spread for the Henderson.
The other thing, and it's mentioned in the video, is that initial bump that's present on the Giraud cases. This is indicative of something interfering at the very beginning of the seating process, leading me to believe there is something up on the inside chamfer. What is the impact of this? Unknown. But I would prefer not to have that issue.
Overall, for me, I made the assessment that I would rather trim off overall length, and the noise difference and the Henderson hard stop were both factors. The time difference isn't a big issue for me because I seldom trim more than a couple hundred pieces at a time - an extra couple minutes difference there was not enough to make up for the other advantages the Henderson brings.