Let me start this off by saying my windows are perfect.
The installers showed up both days an hour late. The lead/head installer let us know from the very beginning that they are not supposed to work weekends and that the boss' son called in sick so I'm guessing that's why he took his time showing up. Both days they forgot materials and took a 2 hour break, but oddly enough the first day they had a caulk gun break and just decided they'd stop for the day. So I'm not sure what they forgot and needed to pick up during their 2 hour break.
Then the installer decided to discuss politics and said Muslims need to be called what they are....terrorist, while referencing a black American wearing a hijab. Now, let me note that my head had been covered both days so I was surprised he didn't just assume I was Muslim, but my husband quickly told him not to discuss politics. I think this made him wonder if I were indeed Muslim so he later asked my husband what faith we were... Again an inappropriate conversation to start.
So my 3 star rating is solely based on professionalism.