Communication about timing and attention to detail.
None
We had a good working history with G&G and hired their services primarily due to their 50-year warranty support. Other companies bids came in cheaper(<$53k) but we feel solid in our decision.
The office personnel were very helpful, the Installation crew was also great. Really everyone I dealt with at G&G were helpful and professisonal. The roof installation itself seemed to reflect good workmanship. Overall a positive experience.