I also have a Xen. The reasons for my choice are similar. I went to my lbs and tried on helmets. The Xen seemed to fit my head well, and it seemed to offer more protection in back, which I was looking for, since most helmets seem to sit up on top of my big old noggin, and I was worried that if I ever fell over backwards the back of my head wouldn't be protected at all. (The Specialized helmet with the Goofy stuck on in my avatar is like that - it rides way up high on my head and offers little protection. But it was only $9.00, and I only wear it once a year - on my class bike ride with my 6th graders.) I wear the Xen for both mountain and road riding. I take the visor off or put it back on as the mood strikes me. Usually I take it off on the road and put it on off-road (am I predictable or what?) The lightness and ventilation are fine, since I never notice a problem in either area.