Hillsounds do definitely have a significant traction advantage over Kahtoolas and they worked quite well on a hike up Kearsage North a week ago but coming down I still had to swap over to my Grivels. Even though I have the closest size of Hillsounds for my pair of boots, when descending I find the Hillsounds slide back a bit and the heel section ends up hanging loose from the heel. I expect its highly specific to the boot design and relative sizing but on that particular day, the Grivels allowed me to get significantly more grip under my heel than the Hillsounds. I also on occasion with Hillsounds end up going down short section of steep ice backwards facing the ice.
The Hillsounds have been my traction of choice in these conditions. They've been sharp enough to gain purchase on blue and black ice, to the extent that regular crampons add little extra value -- the longer spikes of the full crampons aren't needed, as there's no snow between the ice and the boots - and absent hard boots, vertical rails and sharpened tips, the front points don't gain secure purchase unless there are pre-existing ripples in the ice or irregularities in the rock to exploit. Nonetheless, I've still been carrying them. I found my mountaineering ax to be helpful occasionally, but more for cashing in on out-of-reach rock knobs, cracks and stumps than to succeed at getting a decent hold on the ice.
On several trails recently (most notably E. Osceola, Avalon Trail, W-J Trail, Carter-Moriah Trail), there were ice bulges for which I wished I'd brought my Omega's, G-14's, twin tools and dynamic rope. It was usually possible to bypass these and hug trees without too much of a detour, but not always, such as at a choke point just below where the trail on East Osceola's face moderates and gains the ridge.
Peakbagger, I too have found the Hillsounds to have their issues, but also think I've figured them out. A large part of it is a need for care in adjusting the tension and height of the silicone rubber at various points around the circumference of the boot in conjunction with the Velcro strap, but I've also observed a tendency for the bottom link of the vertical chains at the balls of my feet to break. In separate incidents, 3 of my 4 such chains have done this (it's 4 rather than 2 because I'm not consistent about L and R foot placement). In each case, I used my Leatherman pliers to remove the remnants of the old link from the spike plate, and attach the next link up to the plate instead. I've also had this happen to two other hikers in my groups. I think it's a looseness issue, because the problem has not recurred with the shortened chains. So the Hillsounds perform really well, but get good at adjusting them so as not to slide out of place on your foot, and have pliers and/or backup traction.
Sadly, I can also corroborate, from the experiences of hikers in my groups, reports that chain links are pulling through the rubber on late-vintage MicroSpikes.
Apologies to the moderators for contributing to the morphing of this thread from discussion of a winter tragedy to traction choices.
Alex