i made a comment about boalt's ranking recently on LSD, and someone pointed out that historically, boalt has always been in the 7-13 range, and the periodically move up, periodically come down, but they're always in that range. the average ranking was actually 11. so their current ranking isn't out of the ordinary at all.
now you said reputation, so i don't know if you were talking about USNWR rankings, or the assessment scores (which i use to gauage reputation). right now my top two choices are NYU and boalt. not quite harvard and boalt, but hopefully in the coming months, that'll be my new dilemma
anyway, despite an 8-spot difference in ranking, boalt's reputation is only 0.1 points lower than NYU's, out of 10 (add the two assessment scores together). in terms of reputation, boalt is somewhere around #7 i think. it's 0.7 points lower than harvard's total. if you want to practice in CA (as i do), you need to think about reputation in CA. for me, boalt would be the obvious winner in that category, because boalt's rep is strongest in CA, and my reasoning suggests that if you only ask people in CA, boalt's would be higher than the 8.9 you see in USNWR.
however, i doubt that the difference would make up the 0.7 gap with harvard. if i were you, i'd go to harvard. don't make a decision without a visit to both schools, though.