[member="VlPER"] [member="Darth Veles"]
I probably played through the expansion farther than you, Veles, and Makeb is all about either saving the planet from destruction at the hands of the Hutts (Lightside), or still saving (albeit after killing a bunch of them) most of the population of the planet, and still serving the Empire well (Darkside).
The fact that the story there is factional, rather than class-based, is irrelevant. Just the fact that a Sith is able to spare people when it is reasonable or useful to do so shows a great deal of respect, and by that logic, I say there are three types of Sith:
1, The Pragmatist: Only killing when it is useful, not immediately plotting to advance. A truly pragmatic Sith would use both sides of the Force, and would have at least a small bit of respect for their master, and for people too, when it is useful. (Example: Darth Marr, Darth Malgus)
2, The Berserker: This is the kind of Sith that sticks in people's minds, because they are the pawns of the other two categories. With only a couple of exceptions, your stereotypical murderous, evil, organ-eating Sith does not actually advance past a Knight/Warrior rank, simply because they don't have the foresight or non-combat ability to do so. (Example: Darth Vader, Starkiller)
3, The 'I-have-no-name-for-this-kind-of-Sith': Usually rogues, this kind of Sith tend to only kill when it is necessary, but actually have a greater understanding of the Force, because they study the galaxy as a whole, and make allies and enemies almost everywhere they go. When one of these finally comes to power, they might get really corrupted, or they might actually make their territory better. (Example: Palpantine, Count Dooku)