I didnt see Beijing mentioned, but I've recently been there and it was
absolutely amazing. Language was a barrier, but we did not have any issue.
We did not hire any fulltime guide and decided to go around on our own.
we did hire guides at a couple of places for about a couple of hours..
but it was just about 40-50RMB

Taxis were cheap and if you know your place on the map, it
was very easy to point out to the cab driver.

Beijing has a lot of historical and cultual things to see and I've heard
its better than Shanghai.

I'll keep it short, but if you need any more info, I'll be glad to share.