In reply to sean1:
I've been using them for just over 2 years now and I really like them. To answer your question about 7kN... I've taken lead falls on them a few times. Consider the highest force you're (hopefully n)ever going to put on a piece of gear... how about a factor 2 fall on a static sling? I've done that too (long story.. I retired the sling) and it held, no visible damage to wire, solder, nut, etc. So they can take big forces.
In terms of longevity, one of them has a pretty bent wire from one second's attempt at removal but that's almost* entirely cosmetic and can happen to any nuts. Then again, 2 years isn't that long to talk about climbing hardware...
As for other positives (I know, you didn't ask for this...), they seem way more stable in a sideways placement because of the more 'square' cross-section. And because they're not swaged you can rack the entire set on one krab without them getting messy and hard to take off.
Negatives... Everyone else uses rocks and walnuts so may not like leading on your rack. They don't fit as well into the slots that have been worn out by generations of rocks and walnuts!
*almost because in one situation it did make removal pretty tricky as you'd push it up and the bend in the wire would push it further back into the crack...