It is my opinion that there are two types of martial arts in korean. One being taekwondo/tang soo do and the other being hapkido. Hapkido ocourse is almost exactly like daito ryu aikijutsu. Many of the masters of the original kwans had knowledge of the same martial art, so no matter wat they called their scholl or art, they were all still teaching the same art. Ofcourse every master add's in their own bit of flavor, but generally all the striking arts were the same. Tang Soo Do has the same exact techniques as taekwondo go figure... To me having been a practitioner of both and havin seen students from both "styles" I would say the ony differences is the way the techniques are executed. This ofcourse is probably the major difference between the ITF and WTF "styles" of taekwondo. Although now it is widely accepted that the WTF "style" is now geared towards sports; moving away from it's practical self defense applications and focussing on competative sparring. However, there are still schools affiliated with the WTF who are not sports orientative at all and still practice TKD purely for self defense purposes.
_________________________
"Poor is the pupil who
does not surpass his
master" - Leonardo Da
Vinci