When I'm travelling with my wife on a 747 these rows are always our preference. The only issue with row 51 is that the seats are slightly offset from those in front so your don't have a direct view of the AVOD, but it's still a good view and you soon don't notice.

From my experience more often than not food service starts from both the front and back of the cabin so lack of food choice isn't an issue here (most people on this forum never travel behind the curtain of CW or maybe WT+ at a push, so assume most of the details about WT)!