What independent checking have you done? Contact past customers if the shop will reveal them. Google the shop for reviews, etc. With all the automatics nowadays a shop needs them to work on to make profit so manuals are just part of their business. Ask them what percent of their total work on trannys are manuals. If they can't answer with backup think again. Talk to their manual tranny mechanic and ask how many Z32 trannies he has done in the past 5 years. What is the shops number of return for defects in workmanship?