They have awesome support, super fast response times, and amazing uptime. I used to use uptimerobot before but decided to try Downtime Monkey after reading reviews on it and seeing how great the support was. Downtime Monkey monitors your website 24/7 so if something goes wrong it will send an alert right away. The best thing about it is you can setup rules to trigger email notifications when certain events happen. For example, if a visitor hits a URL or does anything other than bounce, that triggers an email notification. It's really easy to setup. You can even add logic to send an automated response to the visitor, so they don't get annoyed if it takes them a while to fix the problem. They are constantly adding new features and they are adding new IP addresses to the pool to ensure there isn't any lag. I would definitely recommend checking them out. Thanks guys!