Well done mate. Good work

There's also pistol grip ball heads, which you can operate one-handed, but they also tend to not have a secondar lock, so you're at the mercy of the grip strength of the springs to keep things locked, which is problematic with heavy lenses. Much more prone to creep in my experience. Another thing to note about ball heads is that they're very flexible, which can be both good and bad. They let you set up a shot quickly, but if you're doing something where you need them to be perfectly level (especially when doing panoramas), they can be much more fiddly to get right. Also, one strength of gimbal heads is that you can adjust it t get the center of rotation in all axes aligned with the optical center of the lens, so that you eliminate parallax when panning AND tilting.

Great comparison, well done 👍

Thanks again for posting Dave. As for the K&F geared head functionality, I can't foresee a need for the ROLL control as employed in this design. Much better IMO to employ a ball and cup levelling control for direct attachment to the tripod base, then add combined geared pan and tilt controls and finally top off with an arca swiss top plate clamp. That should lead to a much simpler, cleaner design. I know it's not geared, but my preference would be a Neewer GM27.

The fiddling or sagging with a ball head is depending on the quality of the ball head, a RRS, FLM and Arca Swiss ball head are not showing any fiddling or sagging of even heavy long lenses. It is related to the material used and the grip on the ball. An exact composition with a ball head is already more difficult than with a geared head thus the ball head should stay exactly in place when locked. With the right amount of friction (depending on camera and lens combination and thus total weight) during composing and a firm locking of the ball after composing. Therefore the purchase of a good ball head is more critical than the purchase of a geared head. The problem with a geared head of low quality is the "play" of the gears which can be compared with fiddling or sagging but in potentially different directions. Buy good and you buy once but not everybody can afford this.

I have only had 3 tripod heads, first was a manfrotto 460mg but it wasn't man enough to hold the dslr and a 500mm lens so i bought a manfrotto 3 way head. Eventually i wanted something lighter and more compact. At the time there was only 3 options for geared heads 2 was from manfrotto and Arca Swiss. The manfrotto geared heads were too bulky / heavy so decided on an Arca Swiss D4 geared head. So despite my comment on your tripod video about spending more on the tripod than the head, at the time the Arca swiss head cost me double the cost of the tripod. Also for those with manfrotto ball heads, some of them have a removable top section that can be replaced with an Arca Swiss mount.