If you are getting AMI errors when creating instances, you are using a version of Barista that is no longer supported, and need to use the latest build.
As of 1.2.0, Barista now supports custom Blender builds. 🎉
Since Barista was written to deal with final renders, it does not directly support add-ons. If you are needing a script that is required during the render process, we would like to hear about it!
For Barista owners, you can theoretically work around this limitation with the custom build feature, and providing the add-on with the build's scripts.
First, make sure you are using an appropriate server for your render. If you have a heavy render and rendering using the lower-cost servers, renders make take a bit longer. While the more expensive servers are in fact more expensive, they are much faster and in many cases can cost less than rendering on the lower end systems.
If you are using a high end server, and the render isn't as fast as expected, keep in mind the settings in your blend file affect the render. Make sure that threads are not limited, and tile settings are set appropriately for CPU rendering setting to 32x32 or 64x64 tiles.
Yes, at this time Barista requires an Amazon account to take full advantage of Barista and cheap/fast rendering using cloud-based services. This account is not only used to store your project files, but to also use their servers to offer amazingly fast renders!