Dark Matter is highly effective I think. Offers good contrast, clear icons, and text is clean against the dark background.
The "light" feature: it's been said that it looks like crap...this I agree with

Too choppy looking.
Personally I think Dark Matters appeals to a wider audience as it looks "polished".
I compared it to some other conspiracy forums and well, Skeptic...I um don't think ATS has much competition in the aesthetics department LOL. (or
content if one looks around a bit on "other sites")
While I did come across a nice looking site (conspiracycafe.com) the pastels are a bit too...serendipity for me (and a little too froo froo). They do
have good contrast though.
There are others...GLP which looks like it was tossed together by a two year old. no-more-lies.be (german) which also has gone for a dark theme and
looks more defined and refined.
Honestly I like the "home" page as well. Although I never really use it, opting to use the recent posts icon instead.
The mouse over comments on each icon(on the home page section) are great and give the board that interactive feel. Also very good feature for those
new to the site and just scrolling around.
The former ATS scheme was good, but this is much better.
Admittedly I have never been much of a fan of "black" backgrounds, but the gradient grays, contrasting icons and text...it all works nicely
together.
The ATS logo in the top left though looks a bit washed out. The glossy effect you had going there was nice and really made it "pop".
I think you've managed a design, features, and function that will please a much larger reach of people, in one or another, there's something for
everyone in this theme.
I also like the active threads being linked atop the page in contrasting colors.
In the old ATS I had a slough of page loading issues, with new servers that's been rectified (as I'm sure most noticed the marked improvement).
Images load fast (although I have never tried to access in dial-up).
The only thing I find a bit irksome is the anonymous post thingy...overkill, waste of space, impossible to sort through...and should anything of value
get posted it's likely lost in the muddle of crap postings.
You've really done a great job and made short work of this massive overhaul. Take a breather and accept a pat on the back or two, or three, or
four... and let the site stand for a bit. It really does come across as a well polished site and while there may be little issues to fidget with here
and there, I think you found a winning CSS style.