Been a long time since I have heard those. Not worth too much outside of some general idea stuff. But better than nothing.
Using straight out of some sources I found the HD25 a bit bloated needing some more juice so the two 95 cans are more optimized for portable sources. The HD25 aren't gonna beat the PMX 95 for soundstage size(PX 95 clamps more so it will be closer) but properly powered the HD25 separates better. Open vs. closed so totally different uses and I can see having one of each, an HD25 and a PX 95 for times you wanted something smaller and didn't need the isolation. They are bit closer to a little brother than the PX100-II was. The drivers just aren't as good of course.
A simple PCX 95 vs. IE8 would be that the PCX is a bit smaller on the stage and more balanced with less bass. The mids on the PCX should be slightly clearer and the treble a smidge more sparkle. The IE will need less volume to drive and have more treble extension. PCX is capable of some more isolation.
Not much really but maybe something useful :)