Not sure if this is old news or not but Infoworld is hosting an ebook sponsored by IBM about Informix, the overview goes a little something like this:
"Today, unprecedented data volumes and shrinking budgets are stretching IT departments to their limits. Now, leading businesses are discovering that success can be derived from the right database-one that does not tie up resources, yet performs better at lowers costs. Read this ebook to discover how IBM® Informix® can help your business."
The ebook talks about the low maintenance overhead, scalability and efficient use of hardware, reliability and embeddability of Informix and even touches on Informix as a warehouse that can utilize compression features to reduce storage, energy and administration costs.