My friend clobbered a hidden rock, the spindle snapped, and his ski went flying. The lower control arm bowed out from where he had the brace but he was able to straighten it later. I think it would have otherwise snapped. On another ride a different Axys went over a barely hidden rock at about 5kmh and the arm snapped right where the brace would go. Ended his day. A few saw it happen and couldn't believe how easy it broke. There's no downside I can see. The bulkhead is really strong.
The Arm Candy braces do fit on all year AXYS RMK sleds. (even the shorter 2019 arms) We have had many customers give great feedback with NONE being an bulkhead failure experience. I personally have bent 2 arms with the braces installed and without the brace I expect the shocks would have been damaged too. They simply strengthen the weakest part of your lower arms but the remainder of the arms can still fail on the biggest hits. (like they should).
We use the Source Innovations Arm Candy braces for both of our Axys sleds and they worked real well! Easy to install, good fit and finish and most importantly they do the job as intended. My son whacked a couple of those "jumping trees" and after buying two lower a-arms for two different instances I got the braces put on. As mentioned when he did hit a tree it bent it but didn't snap it keeping the sled rideable and saving a potential $1500 helicoptor ride never mind ruining the day for our crew. Definitely worth it in my opinion...