I would never put KMP and Coppersmith-Winograd into same place in terms of practicality. KMP gives you very good and fast results on some data (especially data with repeated sequences). Coppersmith-Winograd (and even Strassen) will never be practical on any reasonable data we will see in near future (http://www.ics.uci.edu/~fastmm/FMM-Reference/paoloA.ishp-vi....)