Have tried, codeblocks, netbeans and eclipse with c++ support and qt creator.
Netbeans and eclipse work just fine, but their default window layout and editor settings make me "sick" each time when I install them as one needs to remove/minimize change fonts, size etc in order to make it somewhat readable as the default settings are just covering too much of the screen. It's java based and somewhat laggy on my laptop running ubuntu (different versions over the years) on a cd2 2.2ghz with 2gb ram. I have no idea as to why since I completely reinstalled the distro's several times. That slow and sluggish feeling when one opens the debugger and it slowly crawls through the code is the worst. Same when you are manually going through the function calls (clicking like mad and controlling values), and if you do that a lot (big project) the IDE will totally slow down making you wait 3-5 sec after each press of the button.
Netbeans especially seems to have something against ubuntu as sometimes it will not scale the windows accordingly and some settings will overlap each other. Very irritating.
Code Blocks with the nightly build works best right now in my opinion of those 4 as you can just install and start working without need to fix the font/size, windows etc. It is also the fastest IDE of those I have tried in building / cleaning projects and responds fast when opening/closing prjects, starting program.
Qt creator is like an "mac app". It looks visually very nice, it's simple to use but then again I just dislike when I need to debugg in it. It just doesn't have some of the options that other IDE's have. If you are however developing UI then I highly recommend it because of it integrated gui layout designer.
The Eclipse version that I was using was 5 months old, netbeans 2 months, Qt creator 5 months old and Code Blocks only 20days as I regularity update the nightly builds every month.
If you have not guessed it by now, its Code Blocks that I'm using on my ubuntu distro.
Then again the biggest disadvantage with these IDE's when comparing to the VS2008 that I also use is the debug part. VS just has everything done nicely and you can see the values in vectors, strings etc just by hovering the mouse on the code. When looking inside structures you also skip all the "unnecessary" information so that you dont need to press on like 5 "pluses" and expand the lines in order to see what is saved in a vector.
These were my "daily experiences" with those IDE's on linux as I believe they are important than just listing different features that each IDE has. Everything else seemed to work fine (and I haven't really tested every single feature in great detail). Hope that this will at least help somewhat in deciding what you will pick.
Having said that, Kdevelop you are next on my test list as I haven't tried it yet.