Remove 'significantly cheaper' from Hessian ex. (minor)

demos/monge_ampere_helmholtz.py

@@ -423,10 +423,9 @@ def monitor_interp_Hessian(mesh):
 #
 #    L2-norm error on moved mesh: 0.008385305585746483
 #
-# The mesh movement step now only took 4 iterations to converge and each of those
-# iterations is now significantly faster. This resulted in a total runtime of only 1.23
+# The mesh movement step now only took 4 iterations, with a total runtime of only 1.23
 # seconds, which is up to five times shorter than previous examples. The final error is
-# again larger than the examples where the solution is recomputed at every iteration,
+# again larger than the example where the solution is recomputed at every iteration,
 # but is smaller than the example where we interpolated the solution field.
 #
 # We can summarise these results in the following table: