Their clamp is wider which better supports the mag tube to prevent feeding issues from the tube. These are the clamps that come on the factory JM Pro models. There is an add on QD attachment available as well...
I've always wanted to try the Nordic but have long been happy with CDM Gear. I've used a couple of his clamps and haven't had a reason to try anything else.
There is a "BMT" clamp that can be used with a QD sling swivel, there's also the MTR I think it's called which I have on my 835. It's a slimmer profile which is why I went with that one for the particular application.
Just verified it is the MTR which includes a short rail for a light mount and can use a QD push button on one side. I don't use the rail section on the 835 though.
I just re read some of this, the MTR would not be what you're looking for. It's a magazine clamp that works well when it's not a floated extended magazine tube. My bad.
Nordic is ok. Make sure you tighten it good. I didn't and while shooting 3" magnums the clamp moved and scratched the crap out of my barrel and mag tube.
I don't use a barrel clamp for sling mounts. I drilled a swivel directly into the side of the handguard. There are ridges around the inside of the handguard that support the barrel retaining and if you look, the bottom swivel is drilled into one of those. I just had to file the swivel down a bit so it would fit. It works wonderfully without adding barrel clamps that add time to cleaning or sling plates that create gaps and always seem to cause feeding problems. If you do get a clamp; I like CDM the best. One screw to remove and they come with pads to keep the clamp from ruining your finish. Nordic will destroy your barrel and magazine tube finish.
Misery930 - I like you're idea, and followed your' lead. I used a thread-sert, and set it into the forearm, works like a champ, and no WAY it will ever get pulled out of there.