Originally Posted by poshm
I was surprised on downloading an .lrf file from mobileread that the font seemed to be a lot crisper and darker than what I've been used to reading so far.
The default font for LRF books is heavier than the default font for epub books on the Sony Readers. That's why it looks "crisper and darker".
You can change the default font for both renderers. It's not hard, but it's not exactly easy, either.