You are saying that because they performed feat X with artifacts, they are somehow less than somebody else. Take Ragnos' scepter for instance. You are saying because he has one, it's unlikely that he knew the technique himself or was able to perform it, yet we know Nihilus learned the technique from an ancient sith storehouse. So it's more than likely Ragnos not only KNEW the technique, but created a scepter that would be easier to use for the technique. Hence his "Frightening grasp of the darkside".
No. I am saying that someone who relies on technology or something else for the source of their power is weaker than someone who relies on nothing, and can perform feats on par with them.
Sadow required his technology to perform his feats. Thus, in natural, raw power, the likes of Luke and Sidious are far above him. I consider them more powerful, and by quite a bit.
Ragnos is weaker than Luke or Sidious, because, from what we know, he was the same way. If he were so powerful, DS, why couldn't he have done without the scepter? Given the pragmatism that the Ancient Sith seemed to have, and the fact that the scepter was a powerful weapon, it is highly unlikely that Ragnos just used the damn thing unless he could not perform the technique without it or he couldn't perform it nearly as easily without it, meaning Nihilus's affinity for draining things supercedes his, as Nihilus and Palpatine didn't require technological toys, and yet Nihilus's drain is immense - and Sidious's powers and feats far outstrip any of the Ancient Sith, and so does his raw power.
Conclusion: Because most of them relied on technology to perform considerable feats, they do not compare to the natural power of someone like Luke or Palpatine. If they were to fight, and Sadow didn't have his technology or didn't have time to prepare, and it was a simple-fashioned fight to the death, arena style, Sadow would be obliterated.
Ragnos, again, is also considerably lesser than either Luke or Palpatine at this juncture, because his only claim to fame was performed in the presence of a handy-handy scepter. When he can perform all that Luke and Palpatine has done, without the presence of a technological toy, then I will take some of your beliefs seriously.
In the meantime, don't bother.
And this is why Luke is #1 in all of SW, and Sidious is the #1 Sith. Nobody is arguing that.
You said you put Luke above him as a Jedi, and Palpatine is number one in the Sith category only because "the text says so".
Luke's achievements don't need to be mentioned here. He is more powerful than Palpatine. I mentioned Palpatine's displays of power, and I think it is quite clear that it is above and beyond anything Ragnos or another Sith has displayed.