The reliability of calling support 24/7 and knowing that a cool, knowledgeable and cheerful person will pick up the phone and solve the problem quickly.

Big fan of WPEngine, we have hundred of client sites running on our WPE. High performance (sites can handle 100s of visitors at once without causing issues), staging site saves our developers so many hours of time, site migration plugin makes moving sites easy, support is responsive and 24/7.

Where to begin? WP Engine is the most robust and performing hosting available for WordPress sites, bar none. With WP Engine you'll never have to worry about caching again, you'll never have to worry about backups again, you'll never have to worry about setting up a dev/test site again, you'll have the easiest time setting up SSL, and it'll be free, you'll never have to worry about infected plugins again, and you'll run your site with less plugins than you used to. Turning on CDN is as easy as clicking on a checkmark. Creating a duplicate of your site is as easy as pressing a button and waiting a minute or so. Their support services and live chat are super fast and reliable, and they are open about what's going on. You can definitely host for less at other places, but you'll save so much time using WP Engine, and when you add up all the stuff it comes with out of the box you'll quickly realize that you're actually saving money as well.