Per your request, I did find the overall experience comfortable. Being a last minute trip, BusinessFirst was not available so coach was the class of travel.
The cabin was quite nice and seemed very spacious, since she had the "777 style interior". Having taken the 777 on the IAH-NRT previously in coach a couple of times, I personally prefer the 764 due to the layout 2-3-2 due to the higher window and aisle ratios and decreased center seats.
One complaint with respect to seating: At the floor level, attached to the seat support, the PTV's have a component box that does restrict the leg space. This can be quite annoying in terms of trying to get comfortable on a long flight. Although, it's nothing that a blanket can't soften.
The one thing I would say is that this plane is long! It's very humbling standing at the front and looking towards the back.
As for the inflight services, typical CO, i.e. outstanding. Traveling 100K+ per annum, the one thing that I would also say about CO inflight is that the service is consistent.
It was quite nice to have the PTV's for this flight, this really shortened the flight for me. On the flight down, they did have the Aircraft diagnostics on showing you the operating parameters (speed, distance, wind direction, wind speed, times, and about 15 other basic parameters). This did not have the map however. On the return, there was a reduced set of parameters and the map.
The 764 was not very noisey at all, especially when compared to the DC10-30 that was formerly used on that route. Other's have reported that the plane rides turbulance fairly well, I'd have to agree with this, but I'm not sure how you'd measure this.
From the cabin, you can't fully appreciate the swept back tip of the wings. It is evident from the window, but since you are at the same, or close to, the level of the wing, it is not as pronounced as if you were looking up at it.
All in all, a pleasant experience. I've booked my next trip in a couple of weeks to GIG in BusinessFirst, so if there are any additions, shall keep you posted.