I like the template feature of TeamCity very much but have some suggestions.
I don't see any way how I could put in a dynamic finish build trigger. There is no way to use a parameter value for this since you have dropdowns instead of a text field. Some of these limitations apply also to artifact dependency configuration in the template.
Furthermore I cannot override build steps, like adding build steps at the end for instance. Next thought was to parametrize enable/disabling build steps in the build configuration based on the template, but that does not work.
Basic idea is to be able to parametrize everything in the template, which could make things even more easy to automate or configure.