The reason why most adjusters feel all insurance claims investigators are the same is because, well, they are. 
Although within the PI world this is not a politically correct thing to say, the truth (albeit painful) must be told. Please understand that this is a generalization, but it holds true for most private investigative agencies. The average PI agency serving the insurance claims community is a very small business. They usually only have a handful of investigators, the majority of whom do nothing but local surveillance. They do whatever you ask. If you give them three days of authority, they do three days. They underpay their employees and often, particularly if they get busy, will subcontract someone else to do the work. They have limited resources, no intelligent processes to planning or risk management and you hope that the investigator never has to testify. In short, if you are an average adjuster, you are more likely to work with one of these types of agencies than with one who is consistently better. They almost always underwhelm, thus, the reason why most adjusters feel all insurance claims investigators are the same.
If you work in claims and are sick and tired of “the same” underwhelming work product from PIs, call Sherlock Investigations today.