OB one

I can't comment on the 744 but can comment on the DC 10 with a similar arrangement. I have booked this seat and the aisle seat next to it. The person in the window seat next to the exit door has to sit at an angle as the door really does get in the way. I am 6'1". Luckily Mrs OB one was with me and she is 5'4" so the door did not impact her nearly as muc. Moreover she likes windows and I like Aisles so we were ok. She did complain that it was cold however from a draft, so she needed an extra blanket which the FA brought and commented how that seat was always cold.

I have sat alone on the aisle with a stranger next to me in the window seat, also over 6 feet. he was clearly uncomfortable and really couldn't (wouldn't) turn himself to invade my space, but I knew what he was going through and tried to angle myself a little in the aisle seat and tell him it was ok to twist a bit. If you are on the right hand side of the plane, your left leg is ok and you can stretch it out forever, but the leg nearest the wall is very tight.

Again as one poster said above, you win some, you lose some. But I doubt moving to 51 will make you better off. If it was me, i would stay in the aisle seat especially since you are over 6 feet tall. You do get jostled a bit, but that happens more on the boarding than during the flight. Plus you wil be first for drinks/food where you are.