Although I haven't seen the ranking system in question, I use the Zagat guide from time to time. I assume that the main difference between USNWR and this type of ranking system is that the lawyer ranking system isn't ordinal (from #1 to #[infinity]). That difference means that it's harder to make mountains out of molehills--making small differences appear larger than they are.
According to Liptak, it's not clear how the rankers decide on their rankings, although some of the rankings relate to disciplinary actions.
I've posted a little bit of Schadenfreude on my own blog here.