The Sparks "Criterion" has the same spaced belt loops and horsehide back of the VM2, but without reinforcement at the mouth. It rides a little lower and the cant is greater, which is appropriate for a revolver, IMO. Both wings are slotted for great conformability.
I have a couple of observations, however. A reinforced mouth reduces the tension on the cylinder, making it easier to draw and much easier to re-holster. The VM2 keeps the cylinder on top of my hip bone, taking weight off the belt and putting half the cylinder in a natural hollow in my physique. I'm mostly carrying a 686+, and it remains comfortable and in place all day in a VM3 positioned at 4:00, walking, sitting and driving.