Chose Buddy for auto-deploying a non-profit's website, and have been mostly satisfied.
Building the action flow was pretty painless with Buddy's graphical editor, and it was easy to convert that into a configuration file I could commit to the repository for more fine-grained control once the basics were up and running.
Buddy does MUCH more than we need for generating a Jekyll site and uploading it to shared hosting automatically! We're definitely just sitting on the very tip of the iceberg; maybe we'll use more features as our online presence develops.
My only gripe with Buddy is that I keep having to log in to avoid having the workspace deleted. Updates to our site aren't particularly frequent right now, but Buddy seems to expect activity every two months. On the plus side, there's a generous 30-day window for logging in to keep the workspace active. I just wish they offered a way to sign up as a 501(c)(3) and eliminate the annoyances of a basic free plan. (If they do, obviously I haven't been able to find it!)
We've recently put more emphasis on building out the website, though, and Buddy's support for text-based configuration made it really easy to plug in a "staging" deploy environment with password protection for internal feedback. The web GUI streamlined tweaking the build steps for the site version under development (using a different build framework than the live site), and I expect we'll have a seamless transition to production when the rewrite is done.