What kind of IT M&A Due Diligence report has been most effective for you? Can you share an example?

SOC2 Type II report can give the infosec status and maturity status. 
Also, CMMI level reports can give status update on process and complience maturity.

We utilize a standardized report template that we developed for the report out of what we have gained during due diligence. This report out goes to our Corporate Development, Compliance, Legal, Integrations, and Operational team to ensure all parties have the same report of findings. I cannot share an example of the report, yet I can say we start off with a summary of the target for acquisition, a summary of the high level challenges/risks, with then recommendations to minimize or resolve the risk. This is then followed by the in-depth findings, layout, configuration, apps, etc., and followed by the detailed review of the challenges and risks. 

Besides the standard checks for financial, environmental and other legal skeletons at an M&A target, I look for:

1) Intellectual Property exposure, i.e has the company adequately protected its Technology IP, or has the company possibly infringed on others' IP? 

2) Potential for customer flight to competitors as a consequence of an M&A event, and projected cost of retaining customers.