Irfanview always seemed very clunky to me.
[...]
I am constantly discovering cool new features it has, similar to all the stuff I keep finding in PSPad, my favorite text editor.
-JavaJones
For "clunkiness" I've always thought it the other way around, that XnView was the more clunky thing, but it might just be because I'm so used to the simple Irfanview interface I've set up that the default one in Xnview didn't please me.
About cool new features, I also love that in apps! PsPad is my favourite editor too ;) I'll definitely give Xnview a run for the money this time.