I am a computer professional and have used Proclaim for three months. The media presentations (video and PowerPoint) are stable. This is a main reason for using Proclaim in our church. However, trying to adapt your backgrounds can be a headache, rather time consuming and a risk where data might be lost (or hidden).
To show messages I frequently use Add Item -> Content. After some deleting and adding text fields I finally had a structure I did like. With Proclaim 1.23 I wanted to modify the background picture. However, Proclaim deleted the default text fields from the slide and only kept the one text field I had added manually. This text field covers by default the whole slide, but I had reduced its height so that all fields were visible.
Some suggestions to improve Proclaim backgrouds:
Let us have an extra option to just change the background picture without touching the slide structure and its text fields (not always, but in some cases we may understand better than Proclaim whether a background will fit); give us an option to completely undo our choice of new background; let Proclaim give us a warning before removing text fields unintentionally; improve the structure of the media library to speed up finding proper backgrounds.