I don't really see how progress from war is applicable to the question of whether or not the Sith is evil. Good things come from bad things all the time. Progress doesn't automatically make something good. Psychology has made incredible strides in learning about mental illness by studying mass murderers and serial killers. That doesn't mean serial killers are good.
If one country goes to war with another country because their respective leaders want power or oil or land or slaves, yes, there will obviously be technological progress because of that war. It still doesn't mean war is good. It still doesn't mean the millions who died so those leaders could gain power died for a good cause. It just means a sliver of good came from an evil thing.
THANK YOU! I got caught in that argument a lot longer that I should have. It's basically my point that the Sith code is what people mean when they say that the Sith are not evil. If you follow the code, it, like the other things noted, is not good or bad, it's what you do with it. You can follow the Sith code and be good much like you can follow the Jedi code and be evil.
The rest of Sith culture is what is evil. I'm sure if you broke down each facet, there are probably some good things to find as well, but overall they are evil. You really can't escape that. I'm sure that someone will drop the Obi-wan quote, but honestly, you have to have some messed up lens to be able to see ALL that the Sith do in a positive light.