There was a huge hype about idosing among my friends and we all tried it out for a bit. We tried all sorts of headphones, from stock ipod headphones and 2$ dealextreme earbuds to etymotic research hf5's and some other better headphones. It doesn't seem to depend on the quality of the headphones at all, but mostly on the environment and the person.
I would say that it definitely works for some people. We have some pretty funny videos of my friends absolutely freaking out on the Gates of Hades idose. Some of them would start sweating, panting, even crying and doing all sorts of crazy things and I know for sure that they weren't acting. I know it sort of sounds dumb, and you can find ridiculous/stupid videos on youtube of people but I saw it in person so I'm pretty convinced. At the same time though, a lot of my friends were sound asleep 5 mins into the same track and others just didn't feel anything at all.
Idosing seems to be hit or miss for people. I personally tried a ton of tracks, from the short 5 minute ones to the hour long ones, including Gates of Hades and Hand of God, which are supposed to be extremely "strong". They pretty much all had zero effect on me. I sort of felt tingly for some of the longer ones but I'd assume that anyone who stayed awake for an hour just lying completely still would feel weird.
I'm not sure if the claims of using binural beats to release certain hormones/chemicals is true or not (I doubt it) but the tracks definitely do have some effect for certain people. In my opinion the sound sort of sets an "environment" that could be either tense or calm or whatever and helps your imagination run loose. Combined with being half-asleep, you could definitely have some interesting effects.
The Gates of Hades clip is a little different though, if you're bored you should totally try it. I don't want to "spoil" it, but it's "designed" slightly differently from the other clips so I think that a larger number of people would be able to get some sort of effect from it.