All I know is I've rarely needed to exceed 3000 rpm in the Yeti, and have never gone over 4000 rpm (redline is 5000 rpm)
While the engine is cold, I generally change up around 2k rpm because the engine doesn't like being revved at all while cold, but when it's warmed up, I tend to hold gears until 3k rpm because I find that when I change up at that point, from 1st to 2nd, and 2nd to 3rd, the revs for the gear above are just above 1.5k rpm (below which there's zero power and a horrible vibration in any gear above 2nd), and for 3rd to 4th, and 4th to 5th changes, the revs end up just above the bottom of turbo range (around 2k rpm), so you still get good acceleration.
While I was learning in the petrol-powered cars, I found I would change up very early, as there was still power low down in the rev range, but the diesel Yeti seems to dislike low revs, preferring the mid-range (which doesn't quite make sense, but hey).
It's a Greenline 1.6 diesel if anyone has any idea why that's the case
But back to gear-shifting, I find that the 1st to 2nd change is quite smooth if I either get the car moving, and change into 2nd before 2k, or if I rev it up above 3.5k so that the revs in 2nd are above 2k.
Just my £0.02's worth