Go to Configuration > Stabilization tab > Basic tab
Tick the "Use basic configuration" checkbox.
Around the center stick Acro+ mode reacts like Rate mode, no need high rates the default rates are fine.
Acro+ factor can be set differently for Roll and Pitch.
Default value is set at 40. The bigger the value, the bigger the "Manual weight" in Rate/Manual mixture.
The speed will vary because depending on frame, thrust to weight ratio or how fast motors accelerate.