I've only used VoodooSMS once but can honestly say it was the easiest experience I could've hoped for. The team contacted me to let me know they were around should I have any questions/need help and they also gave me some free credits so I could have a play around before I'd even paid a single penny. The interface is incredibly easy to use and the ability to save templates for both contacts and SMS will save us a ton of time in the future. I especially like the ease for people to opt-out and that this as well as opt-outs, delivery failures etc are all reported. I will 100% be using them again in the coming months.