I have been the lead operator of a MM Minuteman Saddlestitcher with six pockets and cover feeder for ten years+ now. The machine does not run nearly everyday, and we are a single shift operation. The top speed on this machine is 8000 per hour. I typically run it around 4500.
I get the best results from a quality and waste perspective at that speed. I can run some things faster, like 1 or 2 signature booklets, and them some things have to run slower, like web sigs on newsprint.
It typically takes me 30-60 minutes to makeready a pass - that can vary extensively depending on how much I have to change the machine around from the job run prior...
Also keep in mind that the faster you 'feel' it should be run, and depending on how much trim you have, the more one will have to stop just to change out the trash bin. We use rollaway bins provided by the city, so if you have a 48 page letter-size book that was run on 19x25 and then quarterfolded , you're going to accrue a lot of trim in a hurry. So, in some cases, for every ten minutes you run, you may be down five just moving the waste out, sometimes more than that.
When this machine was first installed, my boss kept remarking that the machine would do 8000 per hour, but trying to achieve a high rate of speed continually, in my estimation, is not worth the misfeeds, jams, and possibly, tearing up the machine and the resulting downtime. Also, you need to have enough bodies to man the stations at higher speeds, which we never have here.
Now, there are probably machine operators much more skilled than I am, and maybe my attitude seems a little independent, all I can say is that my books look good and I have never had any complaints from clients to date, have never been short on a run, and have had very little downtime due to breakdowns.
If you feel your operator is too slow, maybe you should look for another... We had another operator, who has since moved on, but when he would run this machine, his product looked like crap and we never knew what the final count was

Good luck to you...