I'd choose neither of those 2 to be honest......the 2 shot is more of a target style release with a fairly stiff dual or triple sear and its easy to get funky if you punch it in the heat of the moment. It really lends itself to controlled shooting with back tension.

The Sabertooth is the least of my favorites of th enew Scott releases. I would choose the Wildcat or Silverhorn over either of the 2 you mentioned.
The Silverhorn (which is a reworked "Rhino") would probably be my pick for string loops because of the way the head free floats and allows the loop to pull straight away from the shot. (Any of the caliper releases force the loop to slip around one or 2 solid jaws). Very smooth and the hook style attachment is quick and reliable.

I have been shooting a Scott Rhino now for 5 or 6 years and about 5 million shots. If I was looking for a new release I would probably go for one of these 2. If you are looking at a Carter as a possible choice the "Quickie" is the best hunting index release they have IMO. Quick and smooth single sear. Doesn't get wild if punched.

Hope this helps.