I trained Sanchin Kata with an Isshin-Ryu club in the early 80s. Of all the old karate I learned, this part was my favourite. The workouts involving Sanchin always left me feeling that I had accomplished something that day.
And there really is something cathartic about hitting your training partners and friends with everything you've got and receiving the same.
There are really some tough buggers out there training Kyokoshin / Isshin-Ryu / Goju, these older hard core Karate styles. Look at George St Pierre in the UFC, who is a Black Belt in Kyokoshin as well as cross training wrestling and BJJ. Very impressive striking.