Wouldn't this bold approach do more harm than good. So, not they will not think that you're pretentious but will think that you're an a$$hole. I think that you should try to remain as honest as possible without sounding like your answering a rhetorical question. I think that most people that improve their mcat score enough to get multiple interviews did so with similar effort and preparation. Many times the same answer will leave the mounths of people trying to explain themselves. Something to the course of "I studied harder and more in depth, I was more mature the second time, I underestimated the test, blah, blah....". I don't really know why adcoms ask this question if they will get the same damn answer every time. I mean what do they want to hear that you were just lucky the second time. Something like, "Yeah, I think that I studied even less the second time that I took the test, I guess it was the beers that I drank that friday night that made me go up those 9 points."
dmitri