The fit was perfect right outta the box. All the vents work amazingly well; you can actually feel air being drawn out the back of the lid! There's also a little skirt under the chinbar that does a good job of keeping the wind off your neck.
Issues? The new VAS visor system is very fiddly compared to the old SAL and SAI version; it was possible that swap visors in less than ten seconds, more like 30 seconds now :-(
Also, there's a draft twixt the visor and seal that makes my left eye water at high speed. I've tried adjusting the baseplates, to no avail. I need to take it to an Arai service bod.
I've had the lid for six weeks now and covered around 2500 miles in it; I'm very happy.