With smaller lists, the results in my test change:

  >>> t1 = timeit.Timer('copy.copy(orig)','import copy;import random;orig = [random.randint(0,255) for r in xrange(10)];')
  >>> t2 = timeit.Timer('orig[:]','import copy;import random;orig = [random.randint(0,255) for r in xrange(10)];')
  >>> t3 = timeit.Timer('list(orig)','import copy;import random;orig = [random.randint(0,255) for r in xrange(10)];')

  >>> print t1.timeit(10000)
  0.0183310508728
  >>> print t2.timeit(10000)
  0.00397896766663
  >>> print t3.timeit(10000)
  0.00760293006897

Which is similar to those results.

This implies more setup cost for copy() and list(), but after that they're faster.