once stable computers will have little error if any at all, i guess human error is more a factor, even that can be done when the sec leaves an answer phone message on the wrong phone ;D this has happened to me
i have offered the demo for a test and will offer some texts to you to give it a good trial
i am looking at a weeks free subscription with 5 free texts to give you the confidance in the system.
if the site returns the message sucsessfully sent them they have deffo reieved it