I have used Pentel Quicker Clicker pencils for about 20 years, and love them. Last time I went to buy more, I couldn't find any, so I bought 3 of these instead - .7mm. They advance the lead in the same manner, but they have two problems:
1. I use mine with a clip board, and often when clipping it on, the top comes off and the lead spills out.
2. When erasing, since you turn the little knob on top of the pencil body, the eraser turns itself back into the tube. Frustrating! And I erase a lot.
If these two things could be fixed, I would be able to give it a 5-star review.