Too me they are two different kinds of fat burners. Both excellent.
The choice would come down to what your looking for in the supplement.
SX is an awesome supplement. It will destroy your appetite, and leave you feeling like you have endless energy. Which sometimes isn't always a good thing. Sometimes at night I'm relaxed, but my mind is racing.
I've gone through like six bottles of DCP. My optimal dosage is 9-10 caps. $$ adds up fast. Its a fantastic repartitioning burner. Its a fat burner you could use while bulking to minimize fat gain. I didn't experience the energy , and the app suppression of SX.
If you notice some DCP specials, its stacked with a stim. DCP/Leviathan Reloaded are a great combo.
If $$ wasn't an issue, I would love to stack DCP with SX.