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