Only problem now is; Actually getting the voicemail.
They won't admit it. Especially with cell phones. If you're out of service area. You won't get the voicemail...for days... as much as a month later. Can't depend on voicemail.
I know this to be true from extensive personal experience. They're all the same. Verizon will jump up and down and scream and yell that this doesn't happen. Thank God there are alternatives in cell phone service.