skidoosh,
The only significant differences between the Ritter Mini-RSK and the Benchmade Mini-Grip is the blade steel and blade design. In colored handles the Ritter uses a different synthetic material called Valox instead of Noryl GTX.
Benchmade uses 154CM in their Mini-Grip while the Ritter Mini is using CPM S30V (although there is a limited edition version of the Ritter that comes with CPM M4 blade steel) so with the Ritter you will be getting a better edge holding steel, and one a bit tougher to sharpen.
For me, at nearly double the price of a regular Mini-Grip, I don't see the Ritter being worth it because you are definitely not getting double the performance or quality.
As to the AXIS-lock........it's great. One of the best blade locking mechanisms out there.
2xTap