Got it yesterday, installed it yesterday.
My initial impression is that it's a subtle, amazing little gadget. I've only been able to go on a couple quick rides so far (I'll make up for it this weekend) but I definitely notice a different feeling in the bike. Off the line it feels like a totally different bike! I might have my fiancée change the setting (without me watching) to see if its just a placebo affect but right now it feels like the best addition I've put on my gs.