Glad you enjoyed it. Hope you got to experience buddy dining, it's the pest part of the A380 F experience and being somewhat phased out...albeit in favour of gate to gate IFE.
My main SEATAC tip is to marvel at the queue for Beecher's handmade cheese. I fear that may be possible for domestic passengers only but I've never seen a more popular airport retail store in the world. Other than that it's a case of managing expectations, although the view can be spectacular as you takeoff with Mt Rainier etc on the horizon. Enjoy!