I wish Armalite would go back to making the brake in multiple pieces like the Leader. The cast version just doesn't break up the design like the old one.
As for the Leader 50, still vaporware until they actually have some on the market. The write up didn't include price, I think the original was more than a Barrett or Serbu. Not gonna generate sells if you're the new kid on the block and cost more.
Bullpup designs don't go over well with most as they tend to hate the look or control placements. Only time will tell how well it does.
ETA: price is $8,200 MSRP!!! Doesn't include shipping and no mention of a CA legal model or if a caliber conversion is available.
2nd ETA: if they would offer it in bare metal as in the video, that would be badass. All they would need to do is put a clear powder coat on it to protect the parts.