John, your comments about expense are certainly accurate and require focus while maintaing profitability. However, SPG will also contribute to increased customer satisfaction, repeat and referral business.
Notwithstanding, the increased gross from higher ELR, increased parts sales(from countermen using SPG), increased productivity for techs, and having report to inspect what your expect. Also, building trust and overcoming misunderstanings with customers is invaluable. Keep watching those expenses, but "don't throw the baby out with the bath water."