I have seen agile done very well and very bad. My experience was when it was done bad it was basically adopting sprints and doing nothing else that would be recognized as agile. The product as a whole was still managed using waterfall. On the good side, I have seen it go very well and produce some great results. KPI's were a well groomed backlog and a good working relationship with the PO. In the good examples, the teams were coming from more traditional process based orgs and they adapted well and we found information sharing and cross team assistance and information sharing ware great. only time the truely agile teams found any issue typically was dealing with non-agile teams and being slowed by waiting on their processes.