Yeah I really would be cautious, I just did the reverse (Flynn -> dokku), and found that even after re-deploying a few images on Flynn it wasn't cleaning up images and disk space was disappearing fast (was hitting my 20GB linode limit without having half of my apps deployed).
So I ended up giving dokku a shot and that thing is lean in comparison, I was able to setup all my apps (about 7 of them) including redeploying some of them many times to get them working, and they only ended up totally around ~10GB on my server. Which left plenty of room for me to also host my music library (~6GB) there too with my music player[1].
> re-deploying a few images on Flynn it wasn't cleaning up images and disk space was disappearing fast
I'm really sorry to hear that you switched off of Flynn. We're aware of this issue, and are in the process of fixing several things that can cause it (it only happens when not using an external blobstore backend like S3). Hopefully you'll try Flynn again at some point in the future!
Yeah I did pop in on Github and report it to you guys[1] and I did really appreciate the speed in which you guys were able to respond to issues. I would like to give Flynn a shot again in the future, but I'll probably at least wait until that issue is solved first ;)
[1] http://benkaiser.github.io/stretto/