I don't want to get an argument started. But, I will answer the question to the best of my ability. If it offends anyone using DC Training I apologize. I am only stating my opinion.
I feel DC Training can give beginners a good foundation in terms of strength but the only thing you can progress on with DC is making strength gains. I can assure no one can keep getting stronger forever. Those following DC Training religiously don't seem to realize that volume and frequency are also forms of overload. Slingshot Training takes advantage of all 3 (Stregnth, Frequency and Volume). Essentially the difference is that I believe volume and frequency, like strength is another very good form of overload. One of the principles of hypertrophy that most bodybuilders agree on is you must consistently increase overload to the muscle in order to stimulate new growth. Well quess what? You can only gain so much strength! Eventually you plateau, but you can always add some more volume or change frequency!
I do not like rest-pause, 6 second negatives and extreme stretching. From my understanding DC Training requires a 6 second negative. It is not that I do not believe slow negatives work because they do work to some degree. My personal thought is that it increases static strength mostly. That said, they are very dangerous. If you do them you will get some stronger but you can use a hand gun to get rid of a migraine head ache. The end result is not good!.
A few things that often happen when training negatives:
Severe muscle strain,
muscle tears,
ruptured muscle..
Torn tendons. One last thing.
If the negitive are so great why don't most powerlifters incoporate them? .
IMO, you'll get hurt a lot using High intensity techniques as described by Mike Mentzer, Dorian Yates and DOGGCRAPP because these forms of training are dangerous. Pushing yourself to extremes is bad for you...PERIOD! And I don't care how much you rest between training sessions!
How dangerous? Let me list a few: I was experiementing with rest pause training and my bicep tendon poppoed during the negative. Six months later a guy at the gym (doing negative only training) tore his shoulder out of the socket. I've seen tricep tendons ripped clean off the bone with rest-pause/heavy negative training. I witnessed one man doing heavy a negative using a leg press machine and the pressure was so great his ankle bones broke. Knees, lower backs, necks, rotator cuffs you name it, I've probaly seen it! And training beyond falure is notorious for causing a ruptured stomach wall. In fact, I experienced it my self during rest-pause.The list of injuries goes on and with extreme training styles!
I do not believe in extreme stretching. Talk with those who have spend some time in a biomechanic lab and they will tell you that extreme stretching doesnt stretch the fascia directly and certainly not to any significant extent thereafter.
THE STS IS ALL ABOUT USING LOW VOLUME, MODERATE VOLUME AND HIGH VOLUME TRAINING (PERIODIZATION) AS OPPOPSED TO BEING OBSESSIVE COMPULSIVE ABOUT EITHER OF THE 3!
Here's a link to a thread that discusses some more differences between STS and DC. http://forums.steroid.com/showthread.php?t=319238
I have learned there's more to bodybuilding that always trying to gain strength with low volume. I hope this helps!