IT seems to me that the question is to look at what is wanted, before deciding what to offer.
My guess is that for most people in a home \ school based role that a NeSS like website will provide what is required. For greater access of data a NOMIS approach for users who want more data and less analysis \ mapping. Over this will be those who want the census output in bulk and little extra.
Whether you agree with my conclusion about groupings and requirements, there does require a clarity when researching the requirements, of who the answer is aimed at, in order that the question can be properly asked of and targeted at the appropriate responder