I subscribe to two forums, the D800 forum and the D4 forum. The D800 forum is vibrant with a variety of different topics being discussed daily. By comparison the D4 forum is dead. Very few posts and little discussion around those posts. Furthermore, I know several of the D4 forum users are also part of the D800 forum and they respond frequently there.
So my question is why?
Is the difference between the intended audiences the reasons? Both are used by professionals but the D4 is the flagship pro camera whereas the D800 is a pro-ish camera that has a wider audience due both to price point and marketing target. Some true pros (I am not) might have less they want to discuss or may see discussing issues as something of a weakness.
Is the difference simply due to the size of the bases? I am assuming that the D800 sells much better than the D4.