Since I tend to expose "sufficiently" - erring on the side of over-exposure to ensure shadow detail - I believe that hte development makes the difference between a good negative and a "great" one.
I touched on this in another discussion here, I think...
Basically it comes odwn to the three kinds of contrast:
Macrocontrast, which is what cn be controlled by burning and dodging dring printing.
Microcontrast, which is wholly determined by type of developer and agitation.
Mesocontrast is the difficult one, and to me the most important. That's the range between grain structure / acutance (microcontrast) and large-scale tonal range (macrocontrast). It is too large to be influenced by agitation, and too small to be manipulated in printing without contrast masks.
Mesocontras is dependent on both the initial exposure, the choise of developer and development. Identical exposures developed in different developers will show marked differences here: I have developed two sheets in compensating developers (divided D23 and Maxim Muir's Copensating pyrocatechol) and the differences are astonishing. Both negatives show about the same density range, but the distribution of densities in the details is totally different.
In my opinion it is this middle range which determines if a negative "sings" or not. The sheets I mentioned above gave prints which were practically identical in tonal range, but very different in terms of visual impact!