Bruce - Much as I loved the D700, for me the B+W fall apart more when converting using Silver EfexPro, I'm not sure whether it's the high dynamic range sensor or the very high pixel density or both, but there is far more tonal gradation with the newer sensors.
Yes: with a higher dynamic range the person doing the RAW development and B&W conversion is in control. One can clip the dynamic range as the camera might or shaped it to suite their purpose.
Or: with a higher pixel density more unique tone values are possible so finer tone gradation is possible. In the days of film for B&W I shot mostly Tri-X Pan in 35mm and Tri-X pan (not professional which was a different film with a different H&D curve) in 120. The 120 negative gave smoother gradation. The smoother gradation could be seen in an 8x10 print and larger.
Regarding grain there are plugins or built in filters in Photoshop and I'm sure other software. I use an old version of photoshop so I don't have access to film grain filters. I have on occasion used a very light, smooth noise on a full image but I can't remember the last time. With some retouching I blur a small area, add noise and then smooth the noise with very light blur to match the noise of the surrounding area. I don't mind very light noise but I guess I haven't added it since using a D300s or maybe back to my D2H.
Grain was a feature of a 35mm prints from Tri-X. It was a given. Lack of grain was a feature of 120 prints from Tri-X. The goal was generally to minimize grain. I souped in D-76, one part developer and two parts water as a compromise between soft grain and image sharpness. Some people mistook my 35mm prints for 120 prints with the right lens, assuming my technique as excellent.
With a D800/E or D850 there is more to work with. In my mind this puts the photographer in control.
Dave