Your situation is all too common. I prefaced what I said with, it depends on what team that you get. Like all things there is a great disparity on the quality of the professional services and experience that you get. My clients were lucky at first and then I found a capable team and requested them for future clients. I probably should not have said that out loud.
In general, my clients feel that ACS is a necessary evil, but they can't live without them. They know that the idea of needing ACS largely reflects a gap in their own knowledge of the system (if they have the right people) or a gap in staffing (just not enough people). Regardless, the hardest thing is that they can't find the words to articulate the value proposition to their leadership team so they kind of use wishy washy terms on why ACS is needed and then nobody gets it. Some think of them as the Sys Admin (they shouldn't be that), Help desk (nope), outsource IT department (maybe but not really). I think of them more as on call expertise. They are the "phone a friend" in case of emergency when they are not helping you create scripts, workflows, evaluate fit of SuiteBundles, or try to help a CFO make due on a promise he/she should not have made (part time magician). The good ones know finance process very well, know the software very well, and can articulate how you can bend the arc of your organization towards NetSuite for better outcomes.