modo - pyAPI test. Returns a list of all selection sets of a selected meshItem. First two methods are old python scripting (the second uses the lx.Service for query). The third method is pyAPI

ListSelSets.py

#!/usr/bin/env python

import time
import lx
import lxu.select

def output(command):
    '''introspect methods and classes'''
    lx.out('$$$$$$$$$ dir $$$$$$$$')
    
    for i in dir(command):
        lx.out(i)
        
    lx.out('$$$$$$$$$$$$$$$$$$$$$')

lx.out('''
###################################
        API TESTING
###################################
''')

lx.out('########### py script ###########')

def pyScript():
    # Stop Watch
    t1 = time.time()
    
    selSets = []
    lx.eval('query layerservice layer.id ? main')
    num_polset = lx.eval('query layerservice polset.N ? all')
    for i in range(num_polset):
        selSets.append(lx.eval('query layerservice polset.name ? %s' %i))
    
    lx.out('selSet: ', selSets)
    
    t2 = time.time()
    
    # Stop Watch
    lx.out('Time: ', t2-t1)
    
def pyScriptSvc():
    lx.out('########### py script with lx.Service ###########')
    
    # Stop Watch
    t1 = time.time()
    
    # Layer service
    layer_svc = lx.Service('layerservice')
    
    selSets = []
    layer_svc.select('layer.id', 'main')
    num_polset = layer_svc.query('polset.N')
    for i in range(num_polset):
        layer_svc.select('polset.name', str(i))
        selSets.append(layer_svc.query('polset.name'))
    
    lx.out('selSet: ', selSets)
    
    t2 = time.time()
    
    # Stop Watch
    lx.out('Time: ', t2-t1)

def pyAPI():
    lx.out('########## API ##########')
    # Stop Watch
    t1=time.time()
    
    # scene service, reference of the scene and a channel read object
    scene_svc = lx.service.Scene()
    scene = lxu.select.SceneSelection().current()
    chan_read = scene.Channels(lx.symbol.s_ACTIONLAYER_EDIT, 0.0)
    
    # current selected items in scene
    selection = lxu.select.ItemSelection().current() 
    
    # Get a int ID for the item type.
    #type_mesh = scene_svc.ItemTypeLookup(lx.symbol.sITYPE_MESH) 
    type_mesh = lx.symbol.i_CIT_MESH 
    
    # Find the first meshItem in the selection
    for item in selection:
        if item.TestType(type_mesh):
            meshItem = item
            break
        else:
            meshItem = None
    
    # Read the mesh channel from the item to get the mesh object
    mesh_obj = chan_read.ValueObj(meshItem ,meshItem.ChannelLookup(lx.symbol.sICHAN_MESH_MESH))
    mesh = lx.object.Mesh(mesh_obj) # mesh object
    
    # Get the selection sets from the mesh with PICK and save them into a list
    selSets = []
    num_polset = mesh.PTagCount(lx.symbol.i_PTAG_PICK)
    for i in xrange(num_polset):
        selSets.append(mesh.PTagByIndex(lx.symbol.i_PTAG_PICK, i))
    lx.out('selSets:', selSets)
    
    # Stop Watch
    t2=time.time()
    lx.out('Time: ', t2-t1)


pyScript()
pyScriptSvc()
pyAPI()

Speed comparison from my machine:

##### py script

selSet: ['01', '02']
Time: 0.000408172607422

##### py script with lx.Service

selSet: ['01', '02']
Time: 0.000134944915771

#### API

selSets: ['01', '02']
Time: 0.000102043151855

The difference between the two py scripts are amazing. And as expected the API is the fastest but also the more complex one.