Hi, I'm also a maintainer :) to answer your questions:
1) we expose ceph in the router, so your apps could use it. This will have to be managed by you however as we don't have a user story for plugging apps into backing services asides from `deis config:set`[1]... Yet.
2) Performance is still something we're working on. When you deploy an application using a Heroku buildpack[2], your app is compiled into a container which sits on top of Heroku's cedar stack, which is around 800MB[3]. It's a beefy stack so fleet will take some time deploying that image. This should only occur the first time it's scheduled onto a new host as future images will just use the cache for that image, significantly speeding up deployment times. If you deploy an app using a Dockerfile and it's been optimized correctly (we have an app sitting under 5MB for test purposes)[4], deployment times should be very speedy.
Hope that answers your question!
[1]: https://github.com/deis/deis/issues/231
[2]: http://docs.deis.io/en/latest/using_deis/using-buildpacks/
[3]: https://github.com/progrium/cedarish
[4]: https://registry.hub.docker.com/u/deis/example-go/