I just bought them as a gift to someone I like very much. After few hours of burn-in I tried them. They seem to be made for use with foam on them. It makes sound much more balanced and warmer. It's hard to say after 5 hrs of warm-up if there's really not enough low tones. They are there, but it's not enough for me. Maybe exercising them longer would straighten them. Maybe using donut shaped foams would be a good idea. Great mids and heights. Clear vocals and no sibilance.
They're very sturdy, fine materials and finish. Volume control together with mini jack socket and plug (extension) is a bit too heavy. Clip would be a nice thing.
Overall deserved flagship title for those buds, can't really complain too much.

OK, I got those buds together with Vedia A10 player but manufacturer sells it for $7. For that price tag it's a real steal. Sound is warm but still natural. Very good bass, nice vocals, clear heights (but a bit behind low and mid), which makes them to the darker side. Excellent percussion and el. guitars rendering, seems to be made for heavier music but performs well on anything. It plays good, comparable with Koss Porta Pro, only sound signature is different. Did I mentioned those are cheap bastards?

Those are AKG K-240 Sextett cardan from mid prod. I bought them on ebay for ridiculous price. If you want to go for Sextetts, keep in mind that elastic bands, inner sponge and ear pads are likely to be replaced. K-240's (MKII) are in production so it shouldn't be a problem though.
As for me, pads are a bit too flat, which combined with a bit bulky plastic grilles makes them little uncomfortable. I used thicker ear pads and now it's all fine. Original cord is good enough, head band seems to be indestructible. Materials and construction are great. Environmental insulation is rather low (semi-open design) so if you want all the details, listen to the music in silence.
 
How they sound? Well, those are the best sounding phones I ever listened (compared for example to Senn's 5**, AKG K-530, Koss Porta Pro and few cheaper ones). Soundstage is wide and clear. No lacking in bass and heights, mids are excellent. Nothing really dominates, response is quite flat. Those are fairly analytical phones, but not totally dry. Few minutes ago I've listened to Vivaldi (Four Seasons). To my surprise, for the first time I heard someone cough... Three times. Yes, you will hear all inperfections of the recordings. I'm just so in love with them.