I have a similar problem. I work from home and rely on my phone (and service) in order to handle customers. In the last 2 months my phone has gone into 'No Service' mode more often than not. As a matter of fact while speaking with my boss earlier (and losing service, of course) once I was able to reach him again he commented that perhaps my phone was taking a day off.
There is no way I will let this plan cost me my job.
PS: I live in Austin, Tx, so I can't see where 'lack of coverage' would be an issue.