Don't be a slew-foot - be a screw foot. With Cullmann.
Okay, you've seen the big new lenses from Nikon and Canon that have substantial foot mountings under the balance points of the lenses. Wonderful idea - it lets you mount them onto substantial tripods and then get steady long-distance shots.
You've seen the new tripods from Cullmann - the Concept series. The 625 and 628 in particular will be of interest to the owners of the larger lenses. What they may wish to consider is an additional little purchase that can really improve the performance.
The removable plate you see on the left in this photo is the one that comes with the smaller Cullmann Concept tripods - the longer one on the right comes with the bigger units. If you get one of these to match your large lens, purchase one of the smaller ones at the same time. The model number is OXC 380.
Take this smaller plate apart - remove the circlip and pop the stainless steel out . Open the rubber lock on the larger plate and slide the screw in.
Now secure both of these screws onto the underside of the Canon or Nikon lens and attach it to your tripod.
With the clamp of the Cullmann head levered down tight, you will find that the lens does not slew out of the plate, and is much more secure. Save the small plate for the future.