ahh, ok i see now.
One of my mates has that 661 evo in brown/green and it's a good looking helmet. It's also a lot lighter than my helmet (661 strike).
As i said, i wouldnt wear my full face for xc/road mainly due to the heat of it and having to take it off to take a drink. It's down to personal preference tho, i've seen plenty people wearing them at trail centres etc. Have you considered a met parachute? - It's half way. Not as strong as a proper full face, but more protection than a normal helmet (also only 15 quid more than the evo at CRC)
In the end, its down to what you feel comfortable with. If you think the risk is large enough to outweigh the drawbacks, you might want to wear a full face.