I like the kpfonts package. It's a nice font and some of the extra symbols it defines are sometimes useful. But I do not like the \sum symbol either in displaystyle or inline. It's too thin and too tall. I tried looking at how kpfonts defines \sum in the hope of just being able to \renewcommand but it does something weird with the maths operators, in order to have package options like fullsumlimits.
How can I get the \sum symbol looking more like the cm sum, for example, without breaking kpfonts package options?
\let\sumop\relaxotherwise all the sums just disappear! – Seamus Sep 13 '10 at 11:18