Of all my (garment) sewing friends I am the only one using rotary cutter. Most people I know have patterns with no seamallowances, so the sort of 'wing it' and add the SA while cutting out. I don't trust my skills, so I always add the 1cm SA to the pattern and cut with a RC. I did try scissors, but then I have to cut next to the pattern, extending the SA and cutting wobbly and all that. Much more precise with RC.