Overall Yelp and Google reviews seem to be positive, and over 50% are positive (maybe closer to 80+%, where lower percentages are affected by lower review counts, where lower reviews carry more percentage weight).
Trying to find completely independent reviews (in unexpected places) is harder. Nixon's places aren't getting a lot of 'press coverage', although I've found a handful of websites that put one or more of Nixon's places in a 'top 10' list.
A week+ ago I posted some text from Linkedin posts that I found that were favorable.
i'd like to find more of those sorts of 'travelog' reviews. Not that I'm looking for reviews purposely skewed to be favorable, but "I was passing by and found this place to be fantastic" are worth at least as much as what you'd find on an official review site.