> Could you please demonstrate an example of the real key sequences
> where repeat-mode could help to greatly reduce the length of
> such key sequences.

An example where such repeating map is sorely missing is gdb.
Until now, stepping through the program was a hassle that required
typing such overly long key sequences:

  'C-x C-a C-n C-x C-a C-n C-x C-a C-n C-x C-a C-n C-x C-a C-n ...'

Now with the following patch, stepping is much easier:

  'C-x C-a C-n n n n n ...'