It’s useful, but must be used with utmost care. Oversharpening is BAD. It’s good when used moderately but soon after that it’ll become simply fugly. Straight lines with start bending, especially in line intersection. Not to mention it’s irreversible.
Simple guidelines would be to never use more than 10.0 for depth and, 2 for blur, and 0.5 for threshold (for awarpsharp).