Guy Bowerman post's about two new Informix white papers. One of them talks about the new compression feature of IDS 11.50.xC4. Be sure to check it, if you feel your data is growing beyond acceptable limits.
The other paper gives an extensive and detailed overview of managing IDS on Windows platform.
Here's the article: http://www.ibm.com/developerworks/blogs/page/gbowerman?entry=new_informix_white_papers