I use one and love it - as stated, the peak is great for keeping out the low Winter sun - very handy this week on numerous occasions.
Mines getting a bit shot at inside here and there but I will definitely buy another when the time is right. Will look at the Shoei helmets aswell though to compare.
The pinlock insert is great in the Tour-X for stopping it fogging up and I also wear a had / scarf to keep out the cold. Works well. I like 'em.