It's not just kmail IMO, despite being on gnome I enjoyed using Amarok up to version 1.4, it was a bit heavy but I liked some of the content and smartplaylist features and it did a reasonable job of helping me search and manage my collection, so I put up with the bloatedness.

I am not sure what sort of deranged mind decided to put the track position bar at the very top (and make it 2 foot long) and then the currently playing track info at the very bottom when due to the over sized and silly navigation buttons there is acres of wasted space above the bar. Add to this the even slower behavior and I had to hunt down a replacement.