How much of the convention is at the Westin? Is it all at the DLCC or does some of it go into the Westin and can you access those parts if you stay somewhere else?
Perhaps 15-20% of the panels occur in the Westin an all are accessible to anyone wearing an Anthrocon badge.
A huge majority of the convention is at the DLCC. There are a handful of panels, a zoo, and a headless lounge in the Westin, all of which can be accessed with your badge regardless of where you are staying.
Note: the Zoo is no longer in the Westin, except for before official opening (Thursday) and after the con officially ends (Sunday evening).
Accessing the Westin is easy. The Westin staff is used to AC'ers passing to the events. To get to them, enter the lobby and proceed LEFT. There will be stairs, and an additional bank of elevators that only goes to the Lobby and the 2 floors above it- those are the areas AC uses. Past the elevators is a set of escalators, and those also go to the 2nd and 3rd floors. The 2nd floor has a variety of smaller rooms for smaller panels (Butler, Cambria, Lawrence, Armstrong), that are good for some panels. The 3rd floor has fewer spaces that are much larger- for when AC wants more space. The escalators also pass the walkway to the DLCC. Unless it's late or there's rain, it might be a better idea to use the street to go from one to the other, however. But yes, most of the convention is in the DLCC.
The stairs are on your right as you come through the revolving door.
As said above, most of the con is in the DLCC, but there are a few things that take place in the westin. I know I attented two meets there last year!
So long as you've got your badge you've got the magical key c: A handful of things happen in the Westin, but the majority of -- everything -- is over in the DLCC.
Even if you're not staying in the Westin, the shuttle busses can help you make the little journey between your hotel and the Con space ^-^