My initial comment is to do with font size / typeface / colors. (I find the font size on the default theme too large and "hard"to read.) Some forums have an option at the top of the page (or under user preferences) to adjust the font size up or down one scale? I'd assume there'd be something similar kicking around in Xenfero? (I also note the font size for regular replies is rather large, and font size in the quoted text is quite small in comparison... Colors and typeface are a bit harder to please the masses, so maybe we'll all just have to hold out until additional themes are added.