The Das hasn't changed at all. I think it's just not considered "the keyboard" by people around here, for whatever reason. I know I'm not a huge fan of the glossy keyboards, but if you're considering a black widow, that clearly doesn't bother you.
Personally, I don't feel the buckling springs are particularly heavy, but the browns are certainly lighter, as is my HHKB. I rather like the resistive feel to them, as I don't really bottom them out all that much.
If you're looking at the Unicomps, you can get a tenkeyless leopold with browns for only $10 more, assuming EK comes back online. Though I'm not sure if that's what you want, considering everything else you mentioned is a full size keyboard. The Das is still cheaper than the leopold though, since it ships for free.