This gives less flexibility, making side grinding easier with faster stock removal. I will explain what happens when you have a grinder with play in the saddle assembly. As the tooth is passing under the wheel and starts to grind, the wheel actually pushes the tooth away from it or pushes the blade down. Another advantage with this style of wheel, which is clearly displayed in the diagram below, is that you can pass under the wheel without having to worry about the motor shaft hitting a tooth or the saw blade. The D4A2 which is a fairly standard wheel for face and top grinding in the industry, allows the motor arbor to extend below the grinding area, interfering in some cases with side grinding.
Most interference occurs in blades with a high degree of positive hook angle.
But the D6A2 allows the wheel diamond section to extend below the shaft, thus eliminating that problem. I am having trouble with the finger sticking to the tooth when I braize the tooth in. I have cleaned it real good and it still sticks. Dan, this is one of the problems that we cover in our two hour tool sharpening training video tape. The retipping fingers are made out of Tungsten Copper.