You will really like your Giraud! If you change calibers back and forth, buy a package of split die lock rings like Hornady or Sinclair make. They make the change over go faster.
I just hold the case in my fingers, and I can average between 14 and 16 a minute, for a pretty good while, say for an hour or so. I'll make a pile of cases on my left, place the machine if front of me, pick up a case with my left hand and place it in the holder, push it down to trim with my right and then pull it out of the holder and dump it on my right side while the left hand is loading another case. Sounds harder than it is!
Back during the summer I had several friends over for a case prep party. I set up the trimmer, set up the annealing machine, had someone deburring flash holes and someone uniforming primer pockets. Everyone brought their sized 223 cases and chose a job. I trimmed about 6500 cases in a little less than 10 hours. Yeah, even though I have farmers hands, my thumb was sore the next day! I thought that was a pretty good average, considering that I had to get up and get stuff a couple of times, change calibers one time, and readjust the annealing machine for another caliber once.
Like I said, you will like it. Lightman