They're not bad. You lose a bit of the actors' facial expressions, but you have a full view of the stage. I've sat there more than once and had no problems. It's not like the balconies at the Palace in terms of being TOO high or distant.
And a lot of the views of what is bad or not will depend on what you are used to. I grew up going to the road houses in Cleveland (the State, which seats about 3300, and the Palace that seats about 2800), and was often up in the mezzanine for those shows. Coming to Broadway, where the biggest house is still just a bit less than a 1000 people than what I was used to, there were very few seats that felt like I was "miles" from the stage.
I would imagine somebody coming from a city like Detroit, St. Louis, or Atlanta where they are used to the Fox Theaters would feel the relative intimacy of the Broadway houses even more so.