I've read a few complaints about the contrast of the text not being great enough. I think the problem is a combination of the light font and the grey text - it's basically not giving monitors enough material to work with, resulting in a washed out appearance. I actually think the font is quite nice, and is in line with the current fashion trends, but it just needs a black colour to give the letters more definition.
If you compare these two screenshots, you can see there is a definite improvement (although annoyingly the scaling of the image reduces the effect)....
Not sure why are they so big??? Wherever I see a link in a forum post, the font size jumps by several points! Wouldn't it make more sense to keep the font size the same, and signify the link in the traditional way with a colour change?
Reactive design a little broken
Just a small thing... on the user profile page, when you reduce the screen size to a mobile device, the 'rank' is having its HTML escaped: