I've been with WPMUDev for just about a year, and I've decided this will be the service I use until I close up shop with my freelance web design business in a few decades. Over the last 6 years I've jumped from host to host, including some of the biggest names like 1and1, Bluehost and others. I'm not leaving. WPMUDev's Pro plugins, 24/7 tech support, competitive managed web hosting and active community are all great highlights. But the one thing that really gets me, is their ability to constantly and persistently iterate and improve their service offerings. They take their member's feedback to heart, and keep pumping out new features and improvements. Seriously, they were good when I joined 10 months ago, yet they're already miles better. They're like the Tesla of WP hosting and plugins.