We are in the early stages of ACS. l think the success of it, as well as implementation, highly depends on the team you get. Any reviews you find on implementation and ACS you find tend to say that same thing. One thing I will say that is very apparent is that if you have a list of customizations you know you want (vs. just still feeling lost with netsuite and that it's not functioning well for you) is 100% hire a contract netsuite developer rather than going through Netsuite or ACS.