They do look at test score, PT scores, inspections scores, in addition to any collateral duties you may have. (You get lots of bonus points for being the President, Vice President, Adjutant, etc.)
Here is an exmaple from my class: Our Vice President had good test scores, was old enough to put him in the slower PRT time group (which meant he scored very well in the out PFT), and he was still only a Candidate LT. Our President also did well in PT tests, had average scores in academic tests, did OK in inspections, and only made out with Candidate LCDR. Our Adjutant scored well on his tests, did well on his inspections, did well in PFTs, and was selected for the RegCom spot. He had a lot of responsibility during OCS. He also got a daily ass chewing from our DI and Class Chief Petty Officer for other people's mistakes. That showed the powrs that be that he is willing to take responsibility even when he is not the one that messed up. That is a good leadership trait. Face time...GOOD face time...and taking responsibility in positions of authority in OCS will make a huge impact on your final candidate ranking.
Aim for that RegCom or Assistant RegCom spot. Our top candidates just told people what to do then went to an extended lunch every day. hehe
"The object of war is not to die for your country but to make the other bastard die for his." - General George Patton (1885-1945)