Some data from linux-2.6 and wine repositories:

linux-2.6:

Execution time 8574.73483 secs, 8539.54468 secs (99.59 %) in external commands)
Execution time 532.61431 secs, 509.50925 secs (95.66 %) in external commands)

-> time reduced to ~6%

wine:

Execution time 1538.62315 secs, 1512.65805 secs (98.31 %) in external commands)
Execution time 341.02903 secs, 331.91908 secs (97.33 %) in external commands)

-> time reduced to ~22%

And this is just one particular function that is cached.

The downside is more used diskspace, the cache for linux-2.6 for example
is 2.9 MiB at the moment.