I have pan heads, an Arca Swiss B1g ball head, and a Wimberly
(sort of a balanced version of a pan head).
I hate ball heads.  If the head is smooth, you can follow
action with any--that's the most important aspect, not
what style it is.  I hate the big lens falls over problem
with ball heads as well as pan heads.  Thus the wimberly
is my favorite for following action.  Second pan.
With the pan, you can tighten one axis to keep your
horizon straight while you pan.  I use a bogen 329
head.  It has the highest carry weight to head weight ratio,
and has a quick release plate with safety stop (the only
one in the bogen line with a safety stop to my knowledge).

Roger
photos at:
http://clarkvision.com
(all the bird photos from Bosque del Apache were done on the 329 pan head;
the Wimberly has a little more vibration than than the 329, but is much
smoother at panning, so I use the wimberly now.)

For the big telephotos (500, 600 f/4, 400 f/2.8) the Wimberley pivot head is
pretty much the new standard, at least at the places I go where these long
lenses are used.  They balance perfectly and it's easy to pan.

But they don't balance well with shorter 2-3 lb lenses (like our 300 f/4 L or
400 f/5.6 L), they are not usable for macro and they are not usable if your
lens doesn't have a tripod collar, so for short lenses you have to have a
ballhead or other solution.

When we go to a place where it's all big lenses (like Bosque or Everglades) we
take the big Wimberley, but when we go somewhere that requires all types of
lenses (like Denali) we take an Arca-Swiss ball-head with a Wimberley Sidekick
(which slips into the ballhead for a modified pivot head) so we can switch
quickly between something for the long lens and something for everything else
that might come by.

I also use the ballhead on my window mount even with the 500 and converters ...
by wrapping my left hand around the ball and lens foot and loosening the ball
with my right hand I can shoot steadily with it, especially with IS, though
it's very poor for panning.

Bill

       A couple of reasons:

       First, most decent ballheads also have a separate panning function
built in.

       Second, not all of the action you might be panning with is going to
be directly horizontal. Planes are a lot more predictable than birds.

       I've found that my subjects can change too rapidly. Sometimes this is
by position. Sometimes, it's because something else has caught my
attention. Having just one control to loosen to aim the camera anywhere it
needs to go is a whole lot easier, in my opinion. And with a good ballhead,
you can set the tension just high enough to hold the camera steady, but
allow repositioning it quickly with a bit of firm pressure, allowing one
hand for the shutter and controls, the other for the lens rings. This works
really well for fast action, sports for example. It also instantly frees
both hands for film or lens changes.

    - Al.

As noted elsewhere, the big 'cannons' require adequate support along with
ease of use. At around 13 lbs (400 2.8), many heads just don't pack the
gear. If you ever try an Arca Swiss or Kirk ball head, you will understand
why they extort, uh I mean exact a premium price;) Not only are you able to
adjust the ball for vertical and/or horizontal movements, they also employ a
tension adjustment dedicated to horizontal panning.

Also, they are not light but are wonderfully built (Arca Swiss, I have no
first hand use w/Kirk).

Shoot'em up, supported or not, Agfa, Fuji, Kodak and all the rest will love
you for it!!

Jim