I wrote a bit of code that will create a cluster on polygon geometry regardless of selection type, eg face, edge or vertex. Speeds things up a little.
import maya.cmds as cmds def makeCluster(): selection = cmds.ls(sl=True) for i in selection: string = str(i) try: object,selected = string.split('.') sel,CVnum = selected.split('[') if sel == 'e': verts = cmds.polyListComponentConversion(selection,fromEdge=True,toVertex=True) cmds.select(verts, r=True) print 'passed edge' if sel == 'f': verts = cmds.polyListComponentConversion(selection,fromFace=True,toVertex=True) cmds.select(verts, r=True) print 'passed face' if sel == 'vtx': print ' no conversion needed' print 'passed vtx' except: print 'object selected' cmds.cluster() makeCluster()