It has pretty good A/D/A converters that go up to 96K, some knobs, some buttons. I've never compared the software to hardware but in my setup, the hardware is much more flexible because most of my processing is outboard. I'm constantly adjusting parameters and it's really nice to have everything right in front of you giving direct feedback.
Ok, i've now compared the two of them. Besides the obvious benifit of the converters and the physical hardware feedback, the processing sounds pretty close. there seemed to be more resolution in the hardware version with minimal limiting and I was able to work it harder than the software version before it started to sound like mush. this could be that there is more math calculations and processing going on in the daw that doesn't happen in the hardware because you have to remember that a lot of things are happening inside of the daw at the same time, not just that particular plugin. I had 3 others listen blindly and they all picked the hardware over the software. They were closer than I thought they would be, but not the same.
I know that the L2 Hardware can operate in unlinked mode. It's a dual mono limiter so, the result is way more open when limitis is hard.
Theplug-insversion can't do that unless you use just a little brain on it...