To be honest, CandW, I don't know, as our grass was faily flat when I did the deed yesterday!
The high setting really is high at 65mm, (2.5"), and hardly tuched the surface, so I dropped it to the middle setting and got a more even result. I want to finish it all at 25mm (the lowest,1") eventually, but after time!
I should know in a week or so, but it's too early to judge your requirement!