I used to use mechanical pencils (or lead holders) with 2-mm leads, and I preferred them over wooden pencils for several reasons. I collected several types of lead holders in different colors and consistently kept the same hardness of lead in each color. This created a color coded system that allowed me to find the hardness of lead I needed quickly. Leads in a holder are quicker to sharpen than wooden pencils, and the leads are less likely to break. Just a few rotations around the sharpener creates a long sharp point. That may not seem like much of a benefit, but a smooth workflow was important to me.
Then I discovered the unique Caran D’arche Grafwood pencils and bought a full set of Staedtler Mars Lumograph pencils and I never worked with mechanical pencils again. These two brands of pencils allowed me to create a wider range of value and texture than ever before.
Here’s more about pencils with quality ratings and a cost comparison chart. Here are my current drawing tools.