Wow that's a long flight, hopefully you have half decent leg room. I love flying but I can't imagine being in a plane for more than 2 hours at very most. Window seat is nice because of the view but the curvature of the plane decreases leg room.
I think the part that people say is a nightmare is going through TSA. I've heard some pretty crazy stories like the agents yelling even at kids. They are basically drill sargeants. Once you pass that though I think everything else is ok. Here in Canada going through security is a brease though compared to the states. I don't fly a lot, but when I do, I always get randomly selected. I thought it was funny. Maybe they're scared I'm going to go all ginger rage on them and blow something up.

Though I think the randomly selected thing really is random, the machine beeps, it's not like they just point at you.
Also flying is 10x more convenient if you don't check any luggage. Find out the max size for a carry on and just put all your stuff in there. Of course, don't bring stuff that would be questionable. Just clothes and toiletry stuff.