Ok, I completed my travel on TK. I flew the 77W SIN-IST and the 330 IST-JNB.
The 777 was really great. As I expected it is much better for two people traveling together to sit across the aisle from each other. You are not that far away and it is possible to have a quiet conversation. The seat to seat phone is also a way to talk.
The 330 was okay. Actually considering it is an angled lay flat seat I was able to sleep much better than expected. I sort of curled up and laid on my side which was more comfortable than just laying straight. For two people traveling together I would recommend getting two center seats so if someone needs to get up they wont disturb the other. Row 2 or 3 might be best if you want to keep somme distance from the galleys and lavs. While it would be possible to climb over the aisle passenger the window passenger would have to put their seat in the upright position and struggle a bit to climb over. The row one seats are nice in my opinion. While you are closer to the galley I don't think it would be too noisy. Since the angled seats when fully reclined go "under" the seat in front of them you will in fact have more room in row 1 since there is no seat in front of you obstructing your room. The tv screen for row 1 seats is further away. If you chose an aisle and window seat in row 1 it would be easier for the window passenger to get out without disturbing the aisle passenger.
Attached are some pictures. If you have any questions let me know and enjoy your trip!!

777 Seat

777 Seat in Bed Mode

Meal on 777

Meal on 777

Meal on 777

330 Seat

330 Seat Legroom

330 C Cabin