We Need a Yelp for Doctoral Programs
Good luck getting honest reviews.  Graduates and recent post-docs are dependent upon good letters of recommendation from their advisors for perhaps a decade after leaving their research groups.The truly disillusioned won't mind complaining, but those with even constructive criticism will feel constrained in their ability to speak out and be specific.The graduate-student experience is deeply advisor-specific.  Professor A may be exploitative, while Professor B may fight tooth-and-nail for student success. The statistics are low, too. Most professors will only graduate a few students per decade.