Even if I more a pencil guy (vintage Conté-Gilbert), I use regularly the cheap Bic Matic (0.7), filled with 2B Conté leads. I used also the 0.7 mm Bic TopGum (a rebadged Pentell), but I don't like the ergonomics (round barrel, moving clip). One on my favourite mechpencil was the Conté Criterium (created in 1939 !), an excellent aluminium 2mm pencil. But with the rise of 0.5 and 0.7 mm pencils, 2 mm leads availability begun to fade two or three years ago. The new version of the Criterium, Bic-labelled, is black and with a plastic barrel. I don't like it at all. I hope someday Bic will replace the Criterium (rather than spoiling it with a plastic new version) by providing a metal Bic Matic. It could be one of the best all-around mechpencil of the world.