I thought I'd leave this here, as there doesn't seem to be any real testing info out there....
I generally hate Grivel products, but tried the Dark Machine ice tools when they originally were released a couple years ago. I liked the balance better than any thing else out there, and used them for three ice seasons. After hundreds of days out with them and a few more birthdays, my aging left wrist started to worsen with pain and became more severe even after moderate use.
I had to find a solution if I wanted to still enjoy climbing ice at the volume we were getting out. In theory, the more aggressive tools would place my hand in an anatomically better position. I tried a number of tools with a more aggressive handle, all meant for dry tooling. Out of everything I tried I did not find a tool that fit my hand, and I did not like the mechanics of their swing.
After loosing a few nights sleep, I carelessly ordered a set of Dark Machine-X tools, as i could not find any to try out, hoping it would work and help with the wrist issue. Out of the box, the swing was slightly off when compared to the regular Dark Machine. I added some small hammers and threw the stock forged junk picks in the trash.
Day 1, I climbed a couple hundred feet of WI3 to establish some kind of expectation on easy ice. To my surprise, they climbed low angle ice better than the regular dark machine. Day 2, I decided to try a very sustained and featured 75m WI5. I found the handle shape interesting as I transitioned from the more straightforward sections of ice and the more complex. The thin straight shape of the handle allows for two distinct swing styles that can be adapted for different impact angles: higher on the grip for simple vertical sections and low on the pommel for featured and overhanging ice. As for wrist pain, it seems to have mostly addressed the problem.
Overall, I have found climbing with the new tool to be less fatiguing and more efficient overall, especially on vertical ice. After 15 days out, they have become my go to tool for everything ice related and I have found no reason to resurrect the regular Dark Machine.
The only negative I have found, is the aggressive shape of the handle makes for a slightly more difficult/ awkward high grip on the shaft. As far as mixed goes, I don't think I'll ever brave potentially dropping them and ruining the carbon fiber handles. I'd be curious to hear from someone on durability outside of pure ice, who has given either dark machines a thorough rock/ big mountain beating.
Cheers
~Dave Jr