My friend out there checks her phone, leaves the house accordingly, and catches it every time. To me, that seems like excellent service.
http://www.spur.org/publications/article/2010-02-01/learning...
In contrast, in Providence or Phoenix (or even when taking the train in NY), when using public transit, I make sure to time everything as well as possible, so that I minimize my wait times. Which means it's a lot more of a big deal when there are delays, because there aren't enough buses/trains to just take the next one available, and I end up waiting for the entire time of the delay.
https://commons.wikimedia.org/wiki/File:Spring-2012-LACMTA-M...
https://commons.wikimedia.org/wiki/File:Metrolink_system_dia...
The extension of the Expo Line (light blue on the first map) out to Santa Monica, scheduled to open next year, should improve things further. The Purple Line extension even more, but that's unfortunately some years out.