The seats are arranged so that that won't work. Each seat has a foot well underneath a monitor, that alone would prevent the face-to-face dining.

I haven't tried J in the 2-class 772, but between the 3-class 772 and the 764, I'd go with the latter. It'll feel a lot less cramped, 2-4-2 seems very crowded. While service is highly dependent on the crew you get that day, overall it does feel a little more attentive and personal in the smaller cabin.