Regarding Atlantic, same, all I have ever heard about them is if they list it as "in stock" on their website, it is in their hands and they will get it out quick.
Additional info for those looking for a good brace. I ordered the new A3 Tactical collapsible one. Price wasn't bad and I have been impressed with their stuff before. Received it, and it is indeed very nice and a quality piece. Installed it, started playing with it, and immediately knew I wasn't going to run it. One reason: collapsed, it blocks the manipulation of the selector. The purpose of me getting this gun was to 1) keep it as a pistol to backpack carry or otherwise (single point bungie sling with it under a winter jacket, anyone?) and 2) fire it collapsed if needed (vehicle, close quarters, on quick deployment). So this was a deal breaker. You'll notice it even blocks it at the next to last stop extended. So the safety isn't clear unless fully extended.
A3 Tactical:
To be fair, I plan on swapping to the Magpul ESK selector anyway, but I can't imagine it will help to the point that it justifies it. So back to the Google machine, and amazingly, the Safety Harbor KES brace was in stock, though without the tailhook. Ordered it, and it's amazing. Not as compact collapsed as the A3T, but overall the rods riding in the channels make so much more sense.