I have an Arai Quantum although previously I only had Shoeis.
The issue I had with my last Shoei, the Qwest, was that the outer shell size was too big for my liking. The chin bar was also rather large and I couldn't do my lifesavers comfortably. I think the XR1100 has a similar issue, for me at least.
The Arai has a considerably smaller outer shell for the same size (I'm a xs or s). It is comfier than my Shoeis and the paint quality is a notch better.
I still think Shoei designs are more modern and better thought out though. They were quieter, lighter and had better visor systems. Ventilation is better on the Quantum however. The Quantum also has a coolmax lining which the velcro on foggys won't adhere to, so I've had to switch back to pinlock which I find can be annoying at night.
I've had to replace a couple of vents on the Arai too, so in terms of features/design I'm not all that fond of it. Still, the bottom line is that it fits me head the best and allows it to move about freely. They take priority over the other features so I'm happy with it.
If I had the money, I'd love to give the Shoei X-spirit 2 and the new GT-air a go though. If the fit & shell size was right I'd go back to Shoei I reckon.