Well, the short answer is that "it's complicated".
There is no single place for Unified builds, and there are several ROMS so it is really up to the developer to post where they see fit. As one example, let's take the most popular and original unified ROM: CyanogenMod CM11. We have our own thread here for Atrix HD
related issues, but the thread for the Razr HD is much more active
. I've recently started monitoring the Razr HD threads because of that.
The good news is that, in the eyes of CM, we are the same device (since we are all grouped into the same msm8960 pool). The bad news is that since they unified, some of those devices got a new KK bootloader while the rest of us are stuck on the JB bootloader. So if you want CM11, you need to only use the one labeled as Epinter's build, because he is compiling it specifically for those still on a JB bootloader. Honestly, ANY rom based on a unified CM11 base that hasn't been specifically modified to handle this issue will NOT work on our phone (or any msm8960 device still on the JB bootloader).
So I think development on a lot of those ROMs that were based on unified builds has stalled until we're on the official KitKat from Motorola. We're sort of in limbo, unless you use Epinter's build. I'm still using the last Carbon Rom, but I'll probably be switching to CM shortly.
Atrix HD (AT&T) - KitKat 4.4.4, CM11; 20140721-N (from epinter)