This appears to be tied to an issue with the user profile as deleting out the joystick section and re-binding all keys/axis has restored the full control range on controller inputs.

Added an image with the steps I took to that corrected it on my end. If you decide to follow, BACKUP YOUR PROFILE FIRST.

http://i.imgur.com/0FNTw82.jpg

Issue could be re-produced by dropping the backup back in place and testing in game.

5/9/15 - Updated link with further instructions and before/after comparison.

Steps needed to correct

1. Navigate to your your A3 profile. This is generally at C:\Documents\Arma 3\YOURNAME.Arma3profile
2. Make a backup of your profile to revert if needed.
3. Open up your profile and scroll down towards the bottom. Your looking for the Joystick List section.
4. Once you find it delete everything between the open and closing brackets as seen to the left in IMAGE A. If done correctly you should be left with what you see in IMAGE B.
5. Disconnect any controllers you use.
6. Load up A3 and delete out all old keybinds that are no longer attached to a joystick. Save profile and quit.
7. Reconnect all controllers.
8. Load up A3 again and re-bind anything you had on the controllers previously then save and quit.
9. Check your profile again and you should only have the controllers in use listed as in IMAGE C.
10. Try everything out and ensure problem has been corrected.

Thanks for the perfectly detailed walkthrough. Yet, though I tried all steps, this doesn't solve my problem.
Are you sure the issues you encountered aren't caused by some wrong tweaking in the ARMA3's controller-customize option?
What happened for my profile file is that it just removed some sensitivity-deadzone-steepnes settings.
Old:
class Joystick2
{

		guid="8406F660-EDE5-11E4-8001-444553540000";
		name="Controller (XBOX One For Windows)";
		offset=512;
		isXInput=1;
		sensitivity[]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
		deadZone[]={0.07,0.07,0,0.07,0.07,0,0,0};
		steepness[]={1,1,1,1,1,1,1,1};
		mode="Custom";
		analogClickHigh=0.40000001;
		analogClickLow=0.2;

};

New:
class Joystick2
{

		guid="8406F660-EDE5-11E4-8001-444553540000";
		name="Controller (XBOX One For Windows)";
		offset=512;
		isXInput=1;
		mode="Custom";
		analogClickHigh=0.40000001;
		analogClickLow=0.2;

};

1. Which of the joysticks did you try? As the "MFG Crosswind 2" has a different offset, sensitivity, deadzone, steepness in your old profile and is put in default in your new profile.

2. Did you check step 4 of the reproduce list? Try a Nato Hunter e.g.; For me hitting left arrow or A key gives approx. 90deg rotation (hand top) while using the analogue input gives about 75...80deg.

3. Can you verify that you reach +-100 for the axis in the controller customize option (use the show button) with your old profile? I reach +-100 and still the response is less than with keyboard.

Hello,

Maybe I know the cause, when you using more than one input controller.

The game engine calculates and uses the mathematical average when using more than one controller.
With this you maybe can not max out the axis.
See: http://feedback.arma3.com/view.php?id=24104

BR
Rob

Hi Rob,

thanks for your input as well. I removed all controllers but one and followed clawz guide to reset everything. Now my profile includes this:
class JoysticksList
{
class Joystick1
{

		guid="8406F660-EDE5-11E4-8001-444553540000";
		name="Controller (XBOX One For Windows)";
		offset=256;
		isXInput=1;
		mode="Custom";
		analogClickHigh=0.40000001;
		analogClickLow=0.2;

};
};

The issue however persists (I uploaded a pic for clarity). I wonder if anyone can reproduce this error -> is it only occuring for me or is the mapping of +-100 controller input just too small (gamewise).

Important:
As mentioned when I go to the controller customize screen and use the show button I can see that I excite +-100 with my analogue controlls, yet the steering does not turn as much as for the keyboard input. That seems to me like a simple mapping error

1. That I can excite +-100 let me assume that there is no issue with the controller itself -> otherwise I'd think I just wouldn't reach the 100
2. The turning of the steering wheel when controller axis has -100 is smaller then when hitting the steer left key (A).

-> Easiest would be if a dev could check what steering angle they map the keyboard key to and what steering angle they map the -100 controller axis to (it really looks like a mismatch there might be the cause)

Experienced the same issue with a new Thrustmaster T16000m Joystick. The solution posted by clawz http://feedback.arma3.com/view.php?id=24064#c92685 worked perfectly, thanks a lot!

Prior to the joystick I used a Microsoft Xbox 360 controller. I'm also using Opentrack and a custom head tracker.

Max value 100 is too small. Need a coefficient of applied to controls. By default, the schematic (xbox one controller) applies the stronger force to aiming. Or need acceleration for axis. Sorry if is a offtop. Sorry for my English.

@GambaDendy i think you mixed somthing up. The 100 is how much % your joystick has moved from 0 to full on 1 axis.
So it cant be more than 100.
What can be chang NOW is the way how it raises till 100 , how much you actually need to move your joystick and the deadzones aka how much you atleast have to move for anything to happen.

To the topic have you tried to bind both posetiv and negativ axis?

Thank you for attention. I bind axis correctly. My problem in that to look around with (xbox360 controller autoschemed) three times more agile than to look around with xbox360 controller from list of customizable mapped, mappedup by xbox360 controller scheme.