For a few months now I've been trying a couple of Arca Swiss ballheads. Before I get into what I think of these, lets first explain how/why I got to choose these over my previous setup, or rather, set-ups. To put this into context, I'm using around 4.5Kg maximum load (DSLR and lens).
Over the years, I've bought and sold a few tripods, but I'm settled on two that I am very happy with for different reasons: an old Manfrotto 441 carbon fibre jobbie, and a Gitzo 5 series (GT5532S). The former is light and portable, the latter is rock solid with practically any camera/lens combo, and relatively light given the stability on offer - although you wouldn't want to carry it more than a few miles.
In hindsight, a 3 series from Gitzo would cover both scenarios: not much heavier than my 'light' tripod, and almost as sturdy as the 5 series. The moral here is 'go expensive early' - a tripod is a long term investment, so don't skimp, you'll spend more in the long run if you buy too cheap!
With the 'legs' sorted I really had 4 needs to cover with heads: everyday landscape head, lightweight landscape head, long telephoto head and panoramic. As a result I accumulated: Manfrotto MN410 Junior geared head (main landscape head), FLM ball head (lightweight landscape), Manfrotto MN393 'gimbal' head and a Nodal Ninja 5 panoramic head.
Quite a collection, and all good in their own rights, but the MN410 and NN5 are both heavy (~1.6Kg). The MN393 is excellent and great value, but the reality is I didn't really use it that much, and I was constantly swopping heads around, or finding myself with the wrong head when, say, a panoramic opportunity presented itself.
So, I decided to rationalise my choices to just two heads, one for light duties to go on the Manfrotto, and another more beefy version to go on the Gitzo. It soon became apparent that a ball head was the only type that would really deliver all my needs described above, especially if combined with L-brackets for my camera bodies.
Panoramics was still a bit of an issue though, until I discovered the Arca Swiss Double-Pano (DP) versions. This clever design puts a rotating pano platform (the kind that would normally go between the head and legs), on top of the ball, just below the camera clamp.
The result is you can level the camera platform using the ball, and then rotate the camera using the pano platform, and it stays completely level to ensure good alignment and error-free stitching. It works remarkably well in the Z1 DP model I bought to attach to the Gitzo. This is a very beefy ball head in terms of stated load capacity (59Kg!), yet not over-heavy (about 750g, depend on which QR platform you choose - there are several choices). It has adjustable friction, and this plus the elliptical ball makes using it with my 300/2.8 and a pro camera body less anxiety-prone than I had expected. Once locked-off, it is rock solid with this combo.
After a few months, I was so impressed I sold all my other heads and bought a second Arca, this time a P0, again the Dual-Pano model and with an identical QR platform as my Z1. With this on the Manfrotto 441 I get all of the capability I need (except long lens use where I would automatically go for the Gitzo/Z1 anyway), but in a light and compact unit. Specs are up to 20Kg load and weight ~400g.
The P-series are in 'inverted ball' design, i.e. the ball is attached to the tripod and the head moves around it. They are unusual in having no knobs protruding, but a single knurled ring runs around the head, and turning this locks or unlocks the head. There is no adjustable tension (the main reason why I don't envisage using this with long lenses), but the ball is elliptical. An advantage of the inverted ball is the exposed surface faces down, so ingress of dirt and moisture is likely to be less of a problem than a conventional 'right-way-up' design.
The DP function works as excellently as with the Z1 (why shouldn't it), the locking mechanism is quick and easy to operate, even with gloves on, and it's design means it doesn't matter how the head is orientated, so there's no scrabbling around looking for the right knob to adjust. It locks down solid to, and it doesn't seem to shift position like some cheaper ballheads do as you lock them. Which is, I suppose, to be expected at the price!
So, overall, I think you've probably gathered that I'm really happy with these heads. The DP system is a great solution and works very well, although you might want to consider adding a nodal rail depending on what lenses you are using, although I haven't found this necessary on lenses 50mm plus.
The heads are slightly let down by a couple of design foibles though. Firstly, the QR clamps do have bubble levels (as befitting any head with panoramic pretensions), but these are impossible to view with a camera mounted! So, you'll be relying on a hotshoe-mounted level or similar. Not a major issue but it would be nice if this could be fixed, as that extra level is another thing for me to lose or forget!
The second and more minor issue is that there is a white indexing mark on the edge of the rotating QR platform and a scale marked on the fixed part of the pano base. Unfortunately, with the QR clamp release facing towards you (i.e. 6 o'clock, which is how I would normally have it), the index mark is at about 2 o'clock, and is thus impossible to see from the shooting position with a camera mounted. May be I'm nit-picking here, but why can't we have this mark at say 5 or 7 o'clock?
To summarise, I'm lucky to be able to have the use of both these heads, but I'd be happy with either (taking into account the limitations mentioned above). Perhaps a P1 (a beefier version - 30Kg/600g) on the aforementioned 3 series Gitzo would be a great single solution, especially if you work in harsh environments and/or wear gloves often?