With shear scraping, the higher the shear angle, the cleaner the cut. I round over the edges of my scrapers. For the outside of a bowl, I use a swept back type scraper with a long wing, drop the handle, and do push/pull cuts. Since the cut is so light, you can go either direction. For the inside of the bowl I use a ) shaped nose. Important here to note that you DROP/LOWER the handle. The reason for this is that you will then only be able to use the cutting edge on the bottom half of the tool. If you hold the tool level, and work above the center of the round nose, the tool is not balanced, and you will get a nasty catch. This is almost identical to what happens with a skew chisel if you work on the high side of the tool and come up off the bevel.
The NRS does have its place, which I consider to be best for end grain on boxes and vessels, and for sweeping across the bottom of the bowl. For the sides of a bowl, a shear scrape is at least as good, and in most instances better. With the NRS, flat on the tool rest, it is still scraping and will lift/pull the fibers as you cut since there is no shear angle. With the high shear angle, the cut is much more gentle, and I get a cleaner surface. With a shear scrape, I find it a bit more difficult to sweep across the bottom of a bowl and eliminate the ripples than doing it with the NRS. When sweeping across the bottom, since you are not going down through the fibers, a scraping cut is generally fairly clean. Also, the finer the burr is, the cleaner the cut. 180 grit burr is good for most situations. For really difficult pieces, then I always head to the 600 or 1000 grit wheel burrs.
robo hippy