I'm not OP, but in general you don't want to use serif fonts on (72dpi) LCDs. Maybe you all have retina display screens at work, on but regular low resolution screens serif fonts slow down reading speed.

See this site for example.

Seems much less readable and I wasn't particularly thrilled with the reasoning that it was "more modern" than the previous font. Readability is more important to me in a news app than modern font choice.