My main purpose was to let folks know a pair of 170's was available. I didn't provide a review partly because I wanted more time on the ski, and partly because it was recently suggested that posting of MA video (which I've not yet gotten, though not for lack of trying) should be a prereq for reviewing skis here. But since you asked:
Overall, I liked them. The only obvious downside of this ski for me, at least as currently configured, is that I felt tilted too far forward by the binding delta -- it's 4.5 mm more than the approximately flat delta I have set up on my 2012 170 cm Stockli Laser SCs, to which I'll be comparing them here. [Using calibrated digital calipers, I measured the deltas for skis+bindings on the Mya and Stockli as 4 mm and -0.5 mm, respectively.]
The factory bevel on the Myas is 2/1. Normally I tune new skis, since factory tunes are often poor, and in any case they're typically not at the 3/1 I prefer (maybe I'd like the PMTS-recommended 3/0.5 even more, but I've never tried that). But the dealer strongly recommend I not have him tune them for two reasons: (1) he said the factory tunes on the narrow Heads are spot-on (by contrast with those on the wider Heads, which he said come out of a different factory and can be lousy); and (2) he said the factory tune is case-hardened, and it's nice not to remove that, since it makes the edge much more resistant to rock dings. Though the tag on the skis indicates they were made in Head's factory in the Czech Republic, rather than Austria, I left it with the factory tune for now, and didn't notice any obvious problems.
I'm 5'7", 150#. I had one day on them at Mammoth, all on groomers with freshly packed powder two days after a storm (i.e., while groomed, the surface was soft). I first spent a couple of hours on my SCs to get a baseline, then spent the rest of the day on the Myas. I spent a few runs playing with binding position, provisionally ending up at what I'll call +0.2 cm (at a BSL of 284, I'm right on the line between what Head calls 0 and what it calls +0.4; I ski the Stocklis at -0.4 cm). Their response to inputs was quite similar to that of the SCs (no significant adjustment required): like the SCs, they responded well to tipping, and carved very well in medium- to short-radius turns (though perhaps favoring a slightly shorter radius than the SCs). However, they felt somewhat easier and less exacting -- I noticed that I felt less worn out than I would have after pushing equivalently hard on the SCs. If they can perform as well or better than the SCs on hard snow and ice (not tested here), but continue to remain easier to ski, we'll have a winner. I'll be interested to see what effect their small but real amount of rocker (the SCs have none) will have on how quickly they hook up at the top of the turn on hard snow.
The Myas did appear to have two downsides vs. the SCs on the softer snow surface. First, the Myas sometimes felt like they were close to breaking loose, a sensation I didn't experience on the SCs. I attribute this to the difference in width -- I was likely closer to over-skiing the soft conditions on the 66 mm Myas than on the 72 mm SCs. Second, I (for the first time in my life) had tip dive on a groomer. I was transitioning from soft packed powder to very soft packed powder, and the forebody of my outside ski dove under the snow, causing a hard fall when the ski stopped short. Don't know why this happened -- I've certainly been on skis narrower than the Mya. Maybe it was the binding delta, maybe I was charging too hard for the conditions, or maybe it was a freak accident. I was going to take the skis off-piste to assess their soft snow performance, but changed my mind after that. Also, I didn't have a chance to try them in moguls.
Note this is all provisional -- I need more time on the ski, in more varied conditions.
Other: The Mya has a more even flex pattern than the SC, which is soft at the tip, moderately firm at the tail, and firm in the midbody. The Mya, by contrast, is firm in both the tip and the tail (vs. the SC, it's much firmer in the tip, and slightly firmer in the tail; correspondingly, it's noticeably thicker towards the tip than the SC). Like the SC, the Mya has two sheets of metal. But perhaps surprisingly, the Myas are heavier than the SCs, even though they are narrower and have a lighter binding -- this is a dense ski! [Viewed from the side, the lower sheet of metal on the Mya appears to be about 30% thicker than that on the SC.] I'd be curious to learn how the Mya differs in construction from the iSpeed, since both come out of the same mold and (according to Head's website) share the same "10% rocker" profile.
I'll add that their graphics are interesting -- the entire topsheet is covered with circles overlaid with a diffraction grating, giving a retro-70s effect that shimmers and changes appearance as you tilt them in the sun (
https://www.flickr.com/photos/111386007 ... 789277174/). The color is brownish-grey with an under-tint of mauve. Everyone thought they were cool-looking.
EDIT: ADDED SOME MINOR CORRECTIONS/CLARIFICATIONS ON 4/16/14.