We've got two of them, both 4.25 inch. To be honest, I don't know enough to pronounce something as "best" or "better than" something else, but I sure do like those guns. Magnum ammo, or wadcutters, doesn't matter. They just shoot.
Is the cylinder length the same as the old pythons? To use 168 gr cast bullets in my old python I have deep seat them in the case.