He was the only practitioner of the lightsaber form Vaapad that didn't fall to the dark side but he wasn't a wielder of dark side abilities like say Revan. I just feel that overall Sidious had knowledge of things Mace didn't or did but never admitted to knowing. Either way I'm not trying to slight either character. I love star wars but Mace had Sidious beat. He was the better swordsman. His swordsmanship was considered legendary among the Jedi. Like I said the only practitioner the use Vaapad and not fall to the dark side. It's commendable.