I've often wondered just how accurate lsatreport.com numbers are. Do we have any idea if one site is any more accurate than another between lsatreport, lsn, the official lsac guide, or any others?

I think LSAT report is the best calculator besides LSN. That said, I think you should take the percent chance calculated, and assume that you have an exponentially better chance the higher your score is (i.e. if you are given a 25% chance, I'd assume something like 30%, with 80%, I'd assume about 95%). This is assuming accurate data, and the data from the law schools is a year or two off.

Oh yea, it's not very close to "accurate," but it's better simply trying to figure out index numbers and it's much better than Chiashu, which is just awful! The "best" way to figure it out is finding a chart on LSAC that gives the exact number of applicants and acceptances from the past year's class. After that is LSN, which is useful for the "bigger" schools because you get a greater number of participants and the numbers show better because of this. After that, LSATreport... then tarot cards, then a Ouija board, then Chiashu.