If you look at the paragraph sample on the webfonts[1] page. you will see it. Also, you could type words like 'flow' or 'follow' into the sample box to see it next to other fonts. This really highlights the extra space on the 'l' glyph.
ah. I only really notice it in multiple L's. It uses the openfont license though. Which means you can legally crack it open using fontforge and adjust the kerning, and redistribute it as pt mono improved if youd like
