Need some advice on JFK-NRT flight

I'm in WBC for this flight with a seat in the lower cabin. There is one upper level seat, although it is 72K in which the lav would be right in front of me. Seat Guru gives this seat a thumbs down as it is very noisy with people going in and out. And I know from past experience when sitting in front of/in back of a lav, it is not a restful flight at all.

I've always enjoyed the service tremendously upstairs because it is so quiet and you don't even feel like you are on the same flight as others. Has anyone sat here before and possibly give me any thought to taking this seat or just staying downstairs?

Thanks.