V1.1 Firmware (01-00.2.01) for the XeRun AXE ESC has improved the following features: 

• RPM/Throttle Matching - 3 Settings: RPM/Throttle Matching, allows you to adjust the way your system will react to changes in load/terrain on trail. The setting can be used to create a "brushed motor" feel. If you like the way a brush motor drives, use setting #1. Setting #2 (Default) is like the original ESC. Setting #3, improves the consistency of the motor RPM over different loads.
• Setup Process - Automatic Motor Pairing Improves: Loose rear endplate, severe impact, or abnormal heat (during the operation) abnormal power output occurs to the motor. This process allows you to reset your motor F.O.C. for the update and calibrates the motor sensors to the firmware. See below for complete details and the simple walk through.
• Motor "punch" or instant start up: The motors response to instant throttle inputs, or "clicking" to full throttle has been improved.
• Drag Brake: Minor changes to how the drag brake operates to to be more smooth and responsive.
• Motor Operation: Improved high rpm efficiency.
• More RPM: Overall, slight gains in RPM, and basic performance
• 550 Size Motor: Update includes additions for the AXE 550 size 2700 and 3300 kv motors