Yes, the small will probably fit you...
I had a Giro G10 before in M and it fit well but I wanted to replace it with something a little more steezy so I got this one on sale. With all the pads taken out a Small fits me perfectly with a beanie on and is very comfortable. No gaper-gap with this one either which was a problem for me with the G-10 - the small front lip covers nicely over the top of my goggles. Overall a great buy!