OK, Tom, here's a short list of *****es:
Name of poster (blue) fades into the gray background, and is visually disassociated from the text of the post. Why is the gray area of the left sidebar taller than that across the top?
Name of poster is less prominent than the Reply buttons on lower left.
Avatar is centered in left sidebar, while everything else is left justified, ragged right.
Too much whitespace -- means fewer posts, less real information, fits on the screen.
Every element is in its own "space" that is not really related with other elements -- there's no visual consistency or alignment of elements.

It's been days now, and I have to admit that it hasn't grown on me in the least; it's actually a deterrent to login and read, because it looks alien, and feels uncomfortable to navigate.