I agree with everyone else. I've had a similar situation last month. A client gave me a Prince EXO3 Black to string with NXT 17 for a friend. I always ask new clients where they previously had the racket strung. This racket was strung at a shop that exclusively on Neos 1000 machines. Since I have Sensor, I wanted to match his previous tension. It was previously strung at 61 lbs. So I strung it at 55.5 lbs on my machine. A few days after stringing my client calls me up saying his friend did not like the tension. They had played on a cold night. His friend was not happy with his play and blamed the recent string job. His friend complained that he needed hit it harder. I told him to keep playing with it, because it could be a caused by a bunch of factors. His friend insisted that the tension was not high enough.
I quickly replied, If I had strung it at 61 lbs on my machine it would lose even more power. This went back and forth, he had 61 lbs in his head. My client agreed with me. My Client brought the racket back to me after some discussion with his friend, and some internet research. He now asks for 54 lbs, on my Sensor. I told him since it's been sitting for a week, it's probably at that tension right now. But hi insisted it be restrung at 54 lbs. He never tried playing with the racket after the first time. Finally I relented and re-strung the racket for the price of string. I've heard no complaints since then.
The cleint I string for had no complaints about he previous re-string, his friend had the problem.