The bike and gator units make a huge difference at large events. A few years back a police officer suffered a cardiac arrest at the marathon and was also resucitated by a bike defibrillator unit.
+1. cardiac arrests happen at these marathons all the time. usually because they have such a heavy EMS presence (added to the whole runners generally being healthy) result in these being saves. Definitely should be publicized more, because it shows the benefits of EMS.