When I owned AL2 650 I installed fork brace after one year of ownership so I had more then enough miles behind me to notice the difference. Rode the bike for one more year then traded it in for '14 DL1000.
My main concern was high wind gusts as I use my bike as a daily rider. I can confirm that fork brace solved my problem of instability in high side winds.
One more thing is important. If you overtighten the brace, it will affect fork travelling. If you donĀ“t tighten it enough, it will have no effect at all on bike. I found out that inner bolts have to be tighten a lot and outer bolts will regulate the rest. In my case they worked the best almost just hand tighten. It was a bit of trial/error but eventually I had it fine tuned and loved it.