I was a VisualStudio + VA-X user before I switched to ubuntu, and needed good auto completion and function navigation features in any IDE.
I have tried Netbeans,Eclipse CDT,CodeBlocks,Geany,Anjuta, KDevelop and finally settled for KDevelop since that was the closest I could get to VS+VA-X.
Eclipse & NetBeans are too heavy & sluggish for my taste. Most of the other IDEs have buggy/incomplete/dumb auto completion & other features; or they want to take control of your code and needs to be imported into projects; or they put 101 files in your source folder. Only KDevelop allowed me to have a simple link to my src folder and let me work. auto completion is not brilliant, but better than the others.
KDevelop doesn't blend well with my Gnome, but I can live with it ;)