I got to handle one today as well, and I noticed some things:
It looked to me like the new front sight / gasblock assembly has a threaded collar for those silencers that fit down over and enclose the front section of the barrel. It may be for something else, but thats what it looked like to me. It even had a thread protector that came with it.
Second, it looked like the muzzle break was threaded on, and then pinned and welded. I thought that pinning and welding was no longer required, as the barrel is supposed to be 16". I am sure though that it had a weld spot on the bottom of the brake.
Third, I only looked at it briefly but the bolt looked to me like the pics I have seen of that new "enhanced" bolt that LMT sells. It was Satin silver in color as well, and had rounded lugs and a bigger extractor.
Overall, I was impressed. It looked to be a well put together rifle, and it was nicely finished. The lower was stamped "Barrett" and the name was also laser etched in a couple of other spots. The ARMS forend looked good, and it had a 40L mounted as the rear sight. I do not know who made the front sight assembly, but it looked good, and functioned well.