I think the ratings in general are pretty accurate, unless someone does something to manipulate them. (ie.. cheat, or resign a gazillion of them ). I know that when I face off against someone about 1700.. I hope for a timeout
I win more games against people below 1400.. I win half roughly against people 1400 - 1600.. and win very little against 1600-1700. My only wins against people above 1700 have been timeouts.