Just joined up to post my impressions of these headphones, which I bought a few weeks ago. I don't listen via headphones a huge amount, so I wasn't looking to spend too big, and these MF-100s were pretty much the amount I was considering. I have also had good experiences with MF products before, with the V-series components.
1. They're a bit tight (I do have a larger-than-average bonce, though), and the suede/alcantara replacement earpads are definitely the ones to go for as regards comfort. Either they'll stretch a little with prolonged use, or I'll just become accustomed to the feel.
2. The lead is a bit short for home listening, but fine for portables. You may require an extension lead for use at home.
3. Not currently owning any iStuff, I can't tell you if the button thing on the lead works or not.
4. Run 'em in, and run 'em in well! When I first put them on, I thought I'd maybe made a duff purchase, as they were very bright. However, on-line opinions suggested they'd need a bit of use to show their true colours. I plugged them into a portable radio, turned up the volume on a music station and stowed everything into a wardrobe so I didn't have to hear anything from them for the next 48 hours.
I'm sure there's more breaking-in to come, albeit nothing as obvious as what has happened so far, but these headphones are now much nicer to listen to - smoother and bigger-sounding. Anyone trying these out in a shop should definitely take this factor into account, asking whether they are straight from the box or not.
They are used with either an old Samsung YP-K5 for portable use or a Furutech ADL Esprit for home listening. The ADL is fed by Foobar2000 (with WASAPI) on my laptop, playing mainly lossless FLAC & WMA.
PS: A week ago, I bought the latest Hi-Fi News & Record Review, and Ken Kessler was very effusive about them in his back page column. Make of that what you will.