I'm split on the issue…
The problem with "publisher reviews" is that they are usually very medium/low in "stars" unless you've actually reworked it many times/have a knack at writing.
The problem with "reader reviews" is that they're either really good or really bad.
I know, for one, that I usually do the "reader" type, because I rarely give anything below 4 stars: anything and everything I read is enjoyable, entertaining, …, and I truly believe that I would read the whole thing if I had it in my hands.
The only cases where I've given 3 stars are when it could do with some reworking.
There are others, I know, who give three stars when I'd give 4.
That's just their way of appreciating a novel, I guess.
Peter Craddock
Arpia, Flight of Dawn