This is how I see it:

Meanwhile the sample size has become quite large in hardware instruments also, so that even the 10 or 100fold of data amount is no more able to create totally different sample quality. It is a saturation curve. The 128MB expansion piano of the Korg M3 sounds almost identical to the 2,8GB German piano of the Kronos. There is still a difference, but the audible differences are shrinking more and more. Whereas in the 1990s we were still in the steep part of the curve, now we are at the left red dot in the part of the curve which is almost horizontal so that increasing data size (x axis) hardly increases realism of the instrument samples (y axis).