I have a shoei head...for day to day street use, I use a RF-1000, and am happy with it. Off road...eh, not so much. It is a bit heavy, and just doesn't flow enough air when you are moving slow(er).
I have a open face helmet from Fly that I wear in the dirt...not bad but I need a bit more room in the forehead area...so it isn't great for multi-day trips...plus it is noisy as all get out, and the visor sucks on the freeway.
As already mentioned, cheek pads are often available in different thicknesses, but the pads around the top of your head are not. I won't buy a helmet unless I can wear it around the shop for 20 minutes first....just like a good backpack...you gotta test it. And of course, if you wear a helmet liner (and why wouldn't you), take that along for the test....they change how the helmet fits enough to be of concern.