An update is planned for December to improve aiming and turning speeds.
343 Industries’ Halo 5: Guardians has been relatively well received for its multiplayer but some players have reported a rather odd bug with the controls. Apparently, aiming diagonally is slower than aiming left and right. You can also face problems with your overall turning speed. Thankfully, it seems the developer has noted player concerns in its latest Halo Waypoint blog.
As Chris King and Scott Sims stated, “This can cause players to become unable to, or inconsistently reach what we call a ‘pegged’ state. The ‘pegged’ state is a region in the outermost range of the analog aim stick in which we blend the players turn speed to a much faster rate.
“This issue is compounded as the control input fluctuates depending on multiple factors – if you are applying even the slightest bit of downward pressure (clenching), moving the stick around the edges a bit (which is why it’s even more problematic when aiming diagonally), or torqueing the stick on the edge a bit more than normal on some controllers.”
A fix is currently in testing with the internal pro team and there will soon be an option to alter all kinds of controller settings including dead zone calibration, vertical/horizontal sensitivities and much more. The update is still a ways off though so look forward to its arrival by December.