Most of my programming (which is limited...) is on *nix distros (so use of available widgets in my programs has been limited to a small subset) - all of them so far have worked fine.
As cautioned you have to know the distro differences, CentOS will use /usr/sbin while Ubuntu will use /usr/bin as generic example.
The only quirky thing I've noticed is widget placement on forms between Gnome/KDE in the design phase, a button on a form may look slightly out of position (just a hair) between the two. I started mocking up the forms on Windows and transferring to my CentOS vmware for coding - handled the issue.
Just my two cent addition.
Regards,
-Mo