Part of my "R&R" is a month of military training.
The reason I don't use the manager is that it doesn't work for what I want done, as far as I'm concerned (after the latest manager update I tried to set up a number of jobs that were complex enough that it should be easier to set it up in the manager than directly in the workshops, but all of them failed to either work at all or work properly):
- It places jobs in the wrong workshops (the block making mason's shop gets furniture, and vice versa, and the magma glass furnace gets bogged down by sand collection orders that should be handled by the ordinary glass furnace off in a corner that exists solely to host those orders).
- Complex orders don't work at all (trying to do e.g. shearing results in cancellation spam, while a once per year repeat order [in the shear/spin workshop by the pasture] produces a single cancellation message when all animals have been shorn. It's possible to write a repeating DFHack script that does shearing with cancellation messages only when you manage to slaughter an animal that was due for shearing, though (but that bypasses the manager completely).
- You can't use it to produce clothing reliably because it can't make decisions based on equipment quality or size, and when running out of source material production restarts with the first item rather than continuing in a round robin fashion, resulting in too many of the first type of clothing and too few of the later ones.
- It can't handle workshops with multiple job types, so it will block all production in all craftdwarf workshops on the job type the dorf that went on a prayer bender served.
- It can't start/suspend jobs based on the calendar.
However, if the manager works for you, that's fine. Keep using it.