Earlier this year or last year this part was shown on bullpupforum, I was critical of the part then because it relied on the spring to hold the receiver lock in place. If the spring broke, then the gun drops...
But the design was changed and when I got my part it can not travel from right to left (as the factory receiver lock does). With it now physically impossible to fall out of the gun if the spring breaks, I think this is a good option for a single point mount.
Being the only integral part made for the AUG that allows single point sling placement, it's kind of neat. Obviously depending on your particular AUG and what you have on it, the balance will vary slightly.
Overall it is a well made option and simple to install. I like it.
Simple does not mean easy though. I'll probably take it out and put it in with some pictures. I didn't look at the instructions included and probably threw them away already. Unless you've taken the lock out before, it's like a small puzzle initially...

Very cool!

But what I really want, no, need to know is where can I get one of those Israeli FAL mats like you have in the background?

Amazon and others have it for about $20. Picked this one up in a group buy a while ago for about half that.

Cool!  I'll give it a search.

I love the GHW Flex swivel
Initially had some concerns like maleante, but have happily been running one for some time now.  

I use an UrbanERT sling I've updated to use QDs, and between the Flex and the Talon optic mount, I'm good to run in either single or 2 point mode.

Is this the same one they offered for sale originally?

I've only had this for about a week. I'm almost positive that this is the only version that was ever offered for sale. When the idea of this was put out, I was pretty critical and others saw the same issue of solely relying on the spring, but this part doesn't even need the spring and it will still stay in. No possible way for it to travel right to left. I can't see this being sold any other way.

So how easy is it to remove the factory part and install this piece?

Removing the factory part is a two second job.
Putting it back in is more complicated.
I'm going to take some pictures of its removal and installation. I'll put it here and on bullpupforum. Bullpupforum doesn't archive old posts, it won't die over there like it will in the archives here.

Thanks

I bought a Blackhawk single point sling adapter.  You can find then for around $7.

I've got one of those somewhere.  Compared to the UrbanERT stock wrap, the BH is crap, loose, ...
The GHW replacement takedown pin with QD socket is better than either...as long as you're running a QD sling or can convert.

Got one of these after seeing this post.  Love it - really nice design.  Took about five minutes to install.  

Joe