I personally think Kaladin would win most situations. Because He has Shardplate, Kelsier does not. Kel probably couldn't move shardplate because it's not metal (as far as I know) Same thing with Shardblades. Kel Might be meaner and sneakier, but Kaladin is much more skilled in battlefield and in many other types of combat. Also I think Sanderson is Extremely biased. Kel (I think) is Brandon's favorite character. So as much as I love his books and all, I think he is the wrong person to ask. Kelsier would just murder Kaladin is his sleep, but in a fight, (general fight) I think it would be Kaladin.
I hope this doesn't come off as "I AM CLEARLY BETTER THAN YOU" or hostile or anything. That's not the intention