For my terrain relief models, a 125mm by 136mm model of Mount LeConte I did yesterday took me about 7 minutes for roughing (0.25" ball nose), then just under 1.5 hours to get the highly-detailed finishing pass done (0.25mm radius tapered endmill). Laser-engraving the trails on the model is about 3 minutes, and lasering the trail map with labels and everything on the reverse is 7 minutes. (I could use a slightly larger radius taper or a slightly larger step size, or both, but I’m really liking the detail I get in the models.)
The large 205mm by 225mm model of LeConte I made for myself took something like three hours, plus or minus an hour. (I don’t recall off hand, but it was about in that range.)
Now, the custom cribbage board I made for Christmas for my parents took much longer to get the design from my head to G-code, but machine time was vastly less than the 3D terrain relief models. A one-hour basic 2D job would strike me as long, but a one-hour 3D terrain relief model would seem pretty fast.
What really makes a difference in my job run times is the plunges. Too many, too slow, or too far can drastically raise the time a job takes. Of course, too fast or too low and you can end up breaking things and maybe having to start from scratch, so there’s a limit, but it’s somewhere to look for getting a bit of time back on some types of jobs. (If you’re doing 10mm slow plunges just to get to the top of your stock, and you’ve verified your stock is flat to less than a millimeter, that’s a lot of air time.)