I tend to agree with your statement about the PFEs being similar to the HF5s in sound.
However...that was before I heard the PFEs with a decent source. Have you tried the HF5s on the HM601 yet pianist?
Essentially a meet is a big room with tables and people bring their own equipment, whether it be amps, headphones, soruces, ears etc. Idea is to listen to things you wouldn't normally get to try, or audition before you buy it yourself. There are some general rules which Fallenangel has outlined at the start but they are straightforward.
In my experience, I cannot feel the seal with the ex600s because of the vent (you don't get that under the water feeling), this might be just me though. When music is not playing through them, isolation is pretty poor, and I can hear everything around me. This is just my personal impression of the ex600s and it might be different for you.
+1 on the HF2s, once you get past the discomfort of shoving the triflanges in your ear, they are comfortable for long periods of time. The distance between the start of the tip and the filter is quite long so your filter clogging problem shouldn't be as bad...they are removable too.