The show floor at West took up the entirety of the 4th floor of the convention center, skybridge and annex 3rd floor, as well as a secondary expo space on the 6th floor of the convention center. It was so big that this year they actually re-arranged to take over the entire 6th floor back ballroom/expo space, displacing the console freeplay area to the annex.
Most of the AAA titles and big players were on the 4th floor. This meant the big Sony and Microsoft booths,(which were again right across an aisle from each other) Twitch, Bethesda, Capcom and Nintendo were all on the 4th floor. The indie megabooth was also on the 4th floor, sort of tucked into a space that juts away on its own which was fitting. Most of the returning booths were in about the same places as they have been previous years. For example Behemoth was at the same entrance to the sky bridge that they have been at for all of the Seattle PAXes I have ever been too. The sky bridge itself was home to Geek Chic, Chessex, Thinkgeek, Warhammar, and Dark Horse, just as it has been for the past few years. Even the Capcom, Microsoft and Sony booths seemed to be in exactly the same location.
The sixth floor expo was more of the small and indie titles, as well as some of the common vendors like we love fine and a few board game demos and vendors. There was a booth for Star Realms and Epic up there, which was always well attended, as well as the official Thornwatch booth.
The fact that the expo is so broken up at PAX West makes it unique. It does create some challenges, since it can be a lot harder to find a given booth since the floor is a maze. However I kinda like how it feels like you have to explore to see it all. In Boston and even San Antonio the floors are much more traditional, being set as rectangles in large spaces. In Seattle though you have lots of corners things are hiding in and back ways to get around, which feels very fitting for a show about exploring game worlds.