Has anyone tried/handled/seen any of the non-Mauser style CRF rifles?

There is this action by Ed Brown:
http://www.edbrown.com/start.cgi/customrifles.htm

Also this one by Sako:
http://www.sako.fi/sako85_features.php

Does the mauser claw maintain any mechanical advantages over these systems?

Or are they too unproven to tell?

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