Being a sewer contractor for twenty five years, I've met a lot of good people in the construction business, Its made the hard work not as hard and the good times better, so yes good people make a difference in the work, that's why you will see groups of contractors working together for years.
Happy workers do better work even when the work is hard.
 An old contractor that I worked for years ago would handout home cooks at times and tell jokes, at that time I did not understand why but mostly he like to do it just that kind of person, He gone now. But I learned some things form him. THANK YOU !! VERN MCCARTY.
 A good contractor will have some subcontractors that they've worked with for years, they will help each other out and it makes for a better job for you. So if you see some old timers that just might be good for your job.
 With underground you need good people to have the job done right, Once its back filled no one will know! Sewer cameras have helped with knowing how the work was done, and the pipe is better, its water tight but you still need to have it installed right, pride in your work is a must, so when the push is on, you not waver. That's why I stop doing fast track housing. with  the faster, faster. that I've scene it just bad for underground in my opinion.