When the F3 was introduced, there were many pros who didn't trust an all-electronic camera, and shunned the F3 for F2's. While you are correct that the addition of the MD-4 gave the camera an eight "AA" battery source of power for the cameras electronics, I still believe that the New F1's electo-mechanical shutter was a much better solution giving one a range of usable speeds in the event of a battery meltdown. And the shutter release for the F3's one mechanical shutter speed was strange to say the least. The FE/FE-2/FA series of cameras had their one mechanical shutter speed marked on the shutterspeed dial, and selecting it allowed one to use the shutter button to trip it. At the very least the F3 could have had the same arrangement.
Additionally, with the F3 Nikon continued its idiotic tradition of positioning the hot shoe on the rewind lever. To be fair they corrected this with the F3P and the F3 Limited. Howver even with these two variants, one still had to use the rewind hotshoe to utilize the cameras TTL metering.
Finally, a personal problem with the F3's aesthetics; I intensely disliked the position of the shutter button in the film advance lever. In my opinion, the shutter button should have been on a separate pylon, as on the F and F2.
As a result, I ended up with a motorized F, motorized F2, and motorized FA, which make up my three-camera kit for street shooting, and I've never really considered buying an F3.
If, however in the unlikely event I change my mind, and get one, it would certainly be an F3P. At least then the hotshoe would be where it was supposed to be; on top of the finder.
And thus, I feel it all started to go downhill when Nikon brought out the F3.