Is the Op/Tech Envy strong enough?

I have been using the classic strap with pro loop connector. I thought since the connector straps were thicker than the 3/8" on the envy that they'd be stronger but then I realized that the actual loop is only a 3/16" while the entire connector loop of the envy is 3/8". The classic is rated for 15 lbs, the envy 10 lbs. The classic ties at the camera while the envy has a loop through and a little sliding grip holder thing. But it is super hard to pull out.
I want to invest in more than one, as I can add one strap to another to make a sling. And I like other colors.

Possible combinations in the future could be a 70-200 f2.8 + a 5D + 600ex. Just kind of the toughest example. So maybe 7 lbs?

http://optechusa.com/e​nvy-strap.html

Look over their site and there should be a reference somewhere to the actual load capacity of the strap (I think it is many times what you would carry if I remember correctly). The 10lbs you quoted has to do with what they think will be comfortable for you with a particular strap.

From their site:
The recommended load is the weight that is most comfortably carried by a particular strap. It is not the maximum load capacity of the strap.

Ohhh nice. Thanks