There should be more than steel alone. No doubt better steel provides more wear resistance, more turning and less sharpening. But an inferior shaped flute would cause clogging or chattering. When I examined the flutes, I noticed the slight difference, but never thought the difference would be so dramatic. May be all the gouges are sharpened to an angle which is deceiving. I made a wax mold of each flute; I then used a hand plane to get rid of the overfill. I scanned them on the flat bed scanner and enlarged them 200%. I was surprised that the scanned images have a 3-D effect. We are all taking about "U" and "V" flutes. But from the pictures, there are variation in flute depth and it is hard to define "U" and "V". Some are hybrids. If you look at the 1/2" and 5/8" (I am using American Standard here) Crown Pro-PM, the 1/2" is definitely one of the tightest "V" flute gouge, but the 5/8" is one of wider "U". I don't think I am qualified to give expert opinion that which is better than which. One of the major complaint about the Glaser tool is the "V" flute tends to clog. On the other extreme is a spindle gouge which is the most open flute gouge. We don't want to use it for side grain bowl turning, so there must be a happy medium in the middle.
Alan Lacer has an article "Putting the Steel to the Test" in current Summer 2008 issue of American Woodturner. I want to do my part and provide some raw pictures of flute cross sections. There are more than difference in steel. I believe with the difference in flute, we can't get the same grind even with identical grinding jig settings. I borrow the 5/8" V gouge from Doug Thompson to do this project. What I had was an early production of the Thompson gouge, I knew he has made some changes in flute design. He has made the flute more open and decreased the depth of the flute. Since mine is no longer available, it would be better to do on the current production. All my other gouges are more than 2 years old, they may not reflect the current gouges. After I have done that, I think I should have included the Thompson "U" gouge, I borrowed one from Doug at today's club meeting. I am going to post the casting when I am done.
There is so much more to be learned.