Could you explain your use case with Sandstorm? I find their homepage to be ambiguous/not really sure what they're offering.
Sometimes it's hard to explain Sandstorm because they have a wide variety of good use cases for it, and there's really not a lot of comparable software packages to it. (It's like ownCloud but it's not like ownCloud, it's like Docker but it's not at all like Docker, etc.)
The managed hosting for Sandstorm is a good step in the direction, because it's very easy to me to move between Sandstorm servers, but I'm not super confident on running my own right now, and it's still in early development as a platform. But Sandstorm on their servers runs the same as Sandstorm on mine, and unlike leaving Google, where I have to figure out how to transplant my data from their proprietary apps to other apps, I can move my apps and data perfectly between Sandstorm servers.
I do place a high degree of trust in Kenton Varda (founder of Sandstorm.io) specifically to keep Sandstorm doing what they should. If I ever feel that trust is misplaced (and I keep a close eye), I'll move.