$ ruby --version
ruby 2.0.0p195 (2013-05-14 revision 40734) [x86_64-darwin12.3.0]

$ ruby method-cache-test.rb 
       user     system      total        real

 defined methods, not busting cache:
   0.270000   0.000000   0.270000 (  0.273828)

 method_missing dispatch, not busting cache:
   0.410000   0.000000   0.410000 (  0.408970)

 defined methods, busting cache with trivial Object#extend:
   1.390000   0.030000   1.420000 (  1.414536)

 defined methods, busting cache with Class.new:
   1.550000   0.090000   1.640000 (  1.638677)

 method_missing dispatch, busting cache with trivial Object#extend:
   1.610000   0.020000   1.630000 (  1.640575)

 method_missing dispatch, busting cache with Class.new:
   1.840000   0.060000   1.900000 (  1.889407)