Here is another vote for the Markins M10. It is relatively light (500g), and holds a 1Ds with 70-200 f/4 rock steady, absolutely no creep when locking it down, in wind etc. Best bit of kit I have bought for years.
I considered the Acrateck and BH-3, but read too many complaints about them creeping when locked down, and the Acratech being hard on the fingers. The M-10 replaces a Linhoff Profi II (kept on uncrewing from the legs, creeped and hurt my fingers!), a Benbo Pro and a Manfrotto (don't remember which one, not one of the new liquid ones, they look pretty good).