When a venue tells you that a room seats 1200 people utilizing theater seating, understand what you’re getting.  Theater style seating provides maximum capacity since there are no tables involved. Chairs will be arranged in straight rows, although rows on on the far right and left of the room can be slightly turned toward the center.  However, there’s nothing more annoying to a conference attendee than to sit in chairs that are latched together without an inch to spare.  Add to that the rows are often tightly arranged with no leg room between rows to navigate.  When hundreds of people start showing up carrying tote bags, purses, coats, coffee cups, laptops and briefcases, it can make for an extremely uncomfortable situation. 
If you expect your attendees to take notes, refer to conference materials, or sit through a session lasting longer than one hour, do them a favor and set up your rooms classroom style or in rounds. Theater seating should only be used for sessions such as a welcome address or short keynote presentation.  If theater seating is the only possible solution, consider asking for a relaxed theater style, which provides for a few extra inches of space between chairs and between rows; in addition, ask for more aisles in the configuration to reduce the length of each row.

Conference and Trade Show Pet Peeves – Theater Seating