Yep, the end caps are generally better placement and see more traffic. I upgraded to one for Fan Expo years ago and saw a huge increase in my sales and the general interest of passerbys. It helps that mine faces out toward the exhibitors area - it's easier to catch the eyes of congoers who may not have intended on perusing down the aisles, but might be drawn in just to buy something on your end table.
Additionally, at least in my particular case, it's two tables instead of one. I split with a friend's business and we have a table each, and the cost is marginally more than a single table down the aisle with the added benefit of increased exposure and foot traffic.