I chose 5EFK for travelling with my wife and son (who was 4 at the time), and I think it worked out great. My son was in 5F, and I was across the aisle in 5K. I didn't find the noise from the galley disturbing, of course, when I sleep I usually sleep with headphones. We did 5EFK both ways IAD-LHR.

4A/K are not aligned with 4EF as another poster mentioned. My first trip in F was a double upgrade from WT+ to F on LHR-BKK, where I was placed in 4K. (Since then, I've only been back to WT+ once in 4 years.) Had I been travelling with the people in 4EF, I could not have conversed with them as easily as I could in 5K.