Royce, just off of experience. Y'all been seeing him coast a lot on tracks. And even then his flow's been vicious. Check his old tracks, he's done the very formatted flow that Elzhi uses on every track. You can call it consistency, but Royce varies the flow.
If you want deeper tracks, check out his older stuff.
Songs like "Life" Off Rock City. King Of Kings.
I dunno, Elzhi is all about his patterns. He'll knowingly sacrifice the magnitude of the punchline for the pattern the fit. Which is cool, it fits him and Elzhi is still ill as fuck to me and getting better. Pretty sure he's much younger than Royce.
Plus Royce been feeding off the skills of dude's like Em and D12 and some real lyricists outside of Detroit for the minute. Elzhi is getting around to it. Slightly different emcees, I give Royce the edge though.