I use curved tool rests on both the inside and outsides of my bowls. Bottom line is that I don't have to move the tool rest and /or the banjo nearly as much with the curved rests, as I do with the straight rests. I have the One Way deep rest for the interior of big bowls, the
12 inch rest for the outside, and one from Craft supplies (blue cast iron) that is S curved that I use on smaller bowls. This tool rest is fine if you are doing a riding the bevel cut, but because it is so wide, it doesn't work as well for the shear cuts. Since I almost never use this cut, it isn't a problem for me. Some day, I will have some smaller ones made, as the S shape has some limits. Sometimes I find that the bowl shape does tend to follow the curve of the tool rest, but most of the time it is the shape of the bowl blank that is the major influence.
The one advantage to using larger heavier gouges, is that you can reach farther off the tool rest with your tool, and not have to be right up to the wood. Again, it means fewer times moving the tool rest and banjo. For me, I find that I can get just as fine of a cut with the heavier tools as I can with the lighter tools. How much pressure I apply to the tool determines how fine or course the cut will be. Of course, the tool needs to be sharp for a fine cut. I have always liked all of my tools to be bigger and heavier than what most other people like. They just feel more comfortable in my hands. robo hippy