Re: Giraud vs Dillon trimmer
I have had both.
I honed the Dillon sizing die to 0.336" for Lapua brass and it worked great. However, when I used other brands of brass, or ended up neck turning to get rid of some donuts, I had to do a second sizing to set the neck tension. Switched from the Dillon to the Giraud for greater flexibility.
Apples-to-apples, both are two operations. With the Dillon, you size/trim and then maybe do a light chamfer. With the Giraud, you size and then trim/chamfer/deburr. In the bigger picture, you aren't saving any operations with the Giraud. But, it does do a nicer job as the cut is more square. You can get a square cut with the Dillon with a LOT of fiddling.
If you weren't going to bother chamfering, it could be argued that the Dillon saves you an operation. You might do this for plinking ammo, but not for precision ammo. I wouldn't attempt to trim and then load the cases successively on a progressive though, as the Dillon trimmer often left quite a bit of shavings inside the cases.