I've used a pair of Pro-Ears Dimension II's over the years. Right now, the batteries need replaced so I just use them for silence.
A couple months ago, I bought a pair of Custom-3's
Klipsch Headphones - IMAGE, Custom-1, Custom-2, Custom-3
These sound fantastic and what I now do is put in my C-3's and put my Dimsions on OVER the C-3's.
The outer noise is greatly attenuated (even more so because of the C-3's sticking in my canal) and I get fantastic sound.
I'll admit to being a Klipsch fan so dilute anything I say because of that...so with that said, these C-3's are the nicest sounding in ear monitors I've ever heard.