In order to help me imagine what the Cham HM might be for me, maybe you Trekchick can tell me what you yourself didn't like about the regular Cham. I know we would ski different sizes, but it may be informative.
As for me, yesterday I demoed the regular Cham 107 in a 184 cm length up at Crystal Mountain for a couple of hours. It had snowed about 8-10" over the last two days, so there was still quite a lot of fairly light (for PNW snow) powder, some of which was quite a bit deeper and barely tracked in the early part of the day. Over the 2 hours or so I went from skiing a) near knee-high freshies/barely tracked stashes off-piste to b) soft snow groomers with a few inches of fresh snow to c) runs that had a mix of piles of slightly consolidated snow and soft/hard moguls interspersed with scraped down real hardpack/crust.
In the deeper snow, the skis were quite fun as long as I kept a centered stance on them and kept the slope moderate. They turn surprisingly quickly for their width and I could quickly and easily shape the turns.I was really enjoying them!! I did notice though that if I tried to take a more aggressive forward stance on them and let them run through deeper stuff, they would plow at times and jerk me forward and back. When on steeper slopes, they didn't seem to run as smooth as I would have expected them and seemed to react a bit too much to changing density of snow - very weird.To be honest, I found that the much narrower Outland 87 (equivalent length 184 cm) that I tried later flowed much more consistently through the deeper 3D snow and seemed to be less affected by changing snow conditions. It almost seemed like the problem with the Chams was something to do with the rocker up front and the shape and stiffness of the tail. The Outland 87 has what seems like a softer and more regularly shaped tail.
The tip on the Cham's definitely flutters alot when running on non-3D snow, but it really doesn't act that unstable - just looks kind of funny.
When running through piles of heavier snow, the tip does hold it's own and kind of knifes through things if it can't run over them and the overall stability of the ski is exceptional. Skiing soft moguls could even be considered fun as long as you approach them in a controlled manner, but when you hit the harder moguls...ouch!!..... the overall stiffness of the ski starts to hurt you. Over hardpack/crusty surfaces though, I started noticing the issue that turned me off of the Cham 97's when I tested them a while ago. It was hard, at least for me, to control the edge in such conditions, either I was totally on edge or totally off, and I had trouble feathering the edge into controlled skids, particularly around the harder moguls. The Cham 107's were not nearly as bad as the 97's in this way. All in all, the 107's really had great stability in mixed conditions but they could really beat you up when you hit hard surfaced moguls and such. The Outlands 87 were not as stable - they would bounce around in mixed hard/soft conditions - but they would not beat you up as much so you can ski them faster.
But, since I am looking more for a backcountry ski, the Cham 107 behavior on hard moguls and hardpack may not be that critical, so that type of ski might still be in the running. Just wondering if the Cham 107 HM version might have more amenable attributes and be a good alternate to the Coomback. I've only skied the Coomback in a 181 on resort so I never got a chance to try it in deeper snow, but I thought that size was too floppy in the tip and they skied short. On the other hand, the 188 cm is a really long ski. Could the 184 cm Cham 107 HM version be a good compromise?