Interesting discussion...and like many here, one that I'm very interested in as well as I'm an ACL reconstruction graduate as well (Nov '04, hamstring graft, tore it while playing indoor soccer and not skiing).
Before my surgery, I knew I would go skiing a few times with my busted knee, so my doc ordered me up a custom Donjoy Defiance which I wore on the 5 times or so I skied prior to my surgery.
After my surgery in Nov, I returned to the slopes 4.5 months post-op in beginning of April '05 and wore my brace everytime I skied for what was left of that season. I hated it. I wasn't totally convinced it was doing anything, and I hated the feel of it on my knee, but I continued to wear it as a precaution. A few months later in September '05, I went to Las Lenas ARG for a 10 days and didn't even bother to bring my brace. I felt fine without it, skied pretty hard and no worries. Never wore the brace again.
Now all that being said, I've looked into the Asterisk with a distant curiosity as i feel that 1) rather than going out and spending a few hunder bucks strengthening your knee and its surrounding ligaments during the off-season and during the season itself is the best injury prevention that you can do and it just keeps you in shape overall....and 2) even if I didn't have that philosophy, I hate wearing/skiing in these types of braces anyway.
Despite my general lack of interest in knee braces due to the reasons I cited above, I AM going to be looking into a new type of preventative knee brace that's recently been brought to my attention and that hasn't been discussed here yet.
This year I am skiing for a clothing company called Aegix Performance Outerwear (www.aegixgear.com)
. Aegix was started by a guy with a bioengineering background and their niche is incorporating soft "armor" into their jackets and pants to help prevent injury. Their jackets & pants are great quality 20,000 mm waterproof/breathable fabric with removable armor in key areas. So they're a ski/snowboard outerwear company with a slant towards incorporating innovative injury prevention functionality into their clothing.
So along these lines, they've taken their bioengineering background, coupled it with the "poron" material that is used in the armor in their jackets & pants and developed a knee injury prevention device called the "Aegix Wing". More information on the Aegix Wing can be found on www.aegixgear.com
under the "Tech" section and you have to scroll down to read a description on the Wing and what its intended purpose is.
I haven't gotten my hands on one yet, but I could possibly have some prototypes to try out soon. Sounds interesting at least in that it seems alot more comfortable to wear than typical braces, and the theory its based upon seems to make sense (to me). Once I try out some prototypes I can report back here with my findings if there is interest.
(sorry that ended being so long).