MEL commands in OpenMaya - good or bad?

Tools Maya
1

As dagModifier of OpenMaya gives user the capability of using MEL commands in OpenMaya.

How efficient is it to use MEL commands inside OpenMaya ? Is it a good approach to use MEL command inside OpenMaya(Maya Python API ) because most of the time whole point of using API is to make the tools faster.

Are there any other Maya Python- API commands besides using dagModifier by which shaders, mesh, light or camera can be created in the Maya scene ?

Here is the example to create a shader using OpenMaya - dagModifier :

class SampleSceneCommand(OpenMayaMPx.MPxCommand):

def __init__(self):
    ''' Constructor. '''
    OpenMayaMPx.MPxCommand.__init__(self)
    
    
def createIt(self):
    ''' Set up the objects which the command will use. '''
    
    # This MDagModifier object will allow us to undo and redo the creation of DAG nodes in our command.
    self.dagModifier = OpenMaya.MDagModifier()
    
    # Create the shading node.
    self.shadingNodeName = 'myMaterial' 
    self.dagModifier.commandToExecute( 'shadingNode -asShader -name ' + self.shadingNodeName + ' phong;' )
    self.dagModifier.commandToExecute( 'setAttr "' + self.shadingNodeName + '.color" -type double3 0.7 0.2 0.15;')
    
    # Create the shading group.
    self.shadingGroupName = 'myShadingGroup' 
    self.dagModifier.commandToExecute( 'sets -renderable true -noSurfaceShader true -empty -name ' + self.shadingGroupName + ';')
    self.dagModifier.commandToExecute( 'connectAttr -f ' + self.shadingNodeName + '.outColor ' + self.shadingGroupName + '.surfaceShader;' )
    self.dagModifier.doIt()
2

Can’t you just use both maya.OpenMaya and maya.cmds? If you really want to use OpenMaya commands over the regular maya.cmds, I think it is only appropriate to use MEL when there isn’t a decent equivalent function, or when you want to “talk” to stuff written and/or controlled by MEL code. A good example or the latter is when you want to go under the hood and access Hypershade or Attribute Editor functions. The other exception is when there is a simple MEL function that would require a ridiculous amount of code to re-implement, for example polyListComponentConversion, though in this specific case you would probably use the regular maya.cmds and not MEL…