I'm a heavy user of my NR scrapers. For us mere mortals even our best work with a gouge will have a tool mark or compression mark here or there and a good NR scraper and time are much more interesting than 80 grit paper. I know the basics - good bur, light touch, even movements, sharpen often, etc. I'm still not settled on the right speed and maybe it's a big "it depends" answer. On natural edge green bowls I try to keep it slow to avoid warping of the tall wings while spinning. 450rpm seems to be a good speed to start at and see if gets a good finish. Lots of variables on those - wood movement, wall thickness, balance, etc. On dry bowls I sometimes can still get chatter marks and wonder if it's too much pressure on the cut or speed, or a combination. It "feels" better at slower speeds, still in the 450-500 range but does that impact the life of my edge? Just curious of some general rules of thumb that would help. I know in general with gouges that faster is better but...