Cin's hype is really impressive, certainly more impressive than Kas'im's by a significant margin. However, his actual showing is the shit my shit shits. What you guys are debating here [which showing is less shittier], is honestly, hard to analyze.
I mean, Cin lost to an Anakin that wasn't actually even trying, as he was choking another Jedi whilst fending off his attacks with extreme ease. As good as Anakin is, that's utter ownage at its maximum. For being considered one of the best in the Order, the Battlemaster and the Chief of Security, he certainly wasn't even close to living up to it all.
I'm not saying Kas'im would win, tho.