Nelson,
Aa the owner of the DD 750X, I can state that it CAN give good grinds, and CAN split points properly. However, both take some finesse and practice.
My first advice to you would be to avoid split points until you get the hang of sharpening standard 118 degree point bits. When you master this, and understand the geometry, I can discuss how to get split points to work right in a way that will make sense in text. It doesn't work well the way the say to do it and usually results in a bit that's cut away way too much. Also, my DD needed to have the axial position of the wheel on the shaft tweaked slightly to get good splits.
In any case, you'll probably have to finnagle the lock nut and the retaining spring on the diamond wheel to get vibration down.
Also, the manual isn't entirely clear on setting the point angle vs the relief angle. The usey the same numbers (i.e. 118 or 135) for both whereas my understanding of drill geometry measures the included angle between the points as the point angle and the relief angle as the angle generated between the cutting edge and the trailing edge of the lips (typically 5 to 20 degrees, usually around 12). The lock screw and pivot adjustment controls the point angle, the chuck setup guide (the part with MTO adjustment) controls the relief angle.
You'll know you have the hang of sharpening (not split pointing) when you chuck up your newly sharpened bit in your drill press, drill a hole into aluminum, and it cuts like butter with a smooth sided hole. The final check is to measure hole diameter vs drill diameter. When they agree within 0.002 or so, you've mastered it! If the drill cuts oversize, your grind is not symmetrical with respect to the chisel point.
Also, the optional 100 grit coarse wheel is a valuable option for large bits and when splitting points on larger bits.
John