Control Stick Loading
This is another secondary parameter which is actually quite important. Apart from force-feedback products that use electric motors to shake the handle (I’ve discussed their highs and lows above), there are two ways to load the control stick: centrally (one spring along the handle) and separately for the X and Y axes (it usually means one spring for each axis although it can be two springs, too).
The central load helps position the stick accurately in the near-zero zone which is good for precise aiming. However, it is less convenient for maneuvering, especially when you don’t see the ground from the cockpit. It is next to impossible to deflect the stick strictly along one axis only, which may prevent you from performing some maneuvers neatly. Many inexpensive joysticks have this kind of stick loading but the particular implementations vary. I guess Logitech's products are the handiest among them as they have a smoother and more predicable movement than the inexpensive models from Saitek and Thrustmaster. The downside is that the stick movement range of Logitech joysticks isn’t long, which negates the advantage of the more convenient stick pressure implementation. Logitech’s mechanics is also inferior to the competitors’ in terms of service life.
Saitek products have an external pressure module. There is a center spring on the stem of the stick that is pressed against the plastic (metallic on the X52 Pro model) plate. Being largely implemented for the sake of visual impact, this system is overall less convenient than in competitor products due to its higher play.
The best implementation of the central loading can currently be found in Thrustmaster's flagship HOTAS Warthog model. The mechanism is based on a central spring but there are also four additional small springs that make it much easier to pass the central position of the stick, which is the common problem of this design.
The highs and lows of axis-independent loading are the opposites of those of the central load design. With this implementation, moving the control stick strictly along the axes requires less effort than the in-between positions (because you only overcome the resistance of the springs of one axis). It is easy to perform maneuvers that require your applying effort along one axis only (such as a loop). On the other hand, it is harder to maneuver accurately around the central stick position, especially when the springs are stiff, because the stick tries to move where meets the least resistance.
Despite some inconveniences, the separate loading looks preferable, but only if the springs are not very strong. There are but few such joysticks, though. I can only think of joysticks from CH Products, the affordable SpeedLink SL-6640 Black Widow (which copies CH's control stick design) and Thrustmaster's HOTAS Cougar. But the Black Widow has poor electronics, just like the rest of SpeedLink's products, whereas the springs of the HOTAS Cougar are so strong that I found it very difficult to move the control stick near its central position (but some users think that's normal).