Replacement for Pneumatics and Linear Actuators

[magnets]

This is a very cool concept. I can see how it would be useful in moving manipulators and catapults in a way much simpler than some teams currently do.

A few questions/comments:
Can in both push and pull? I'm having a hard time visualizing.

What sort of rods are used, and what type of linear bearings are used?

What exactly is the spring like thing at the end?

How much force/twisting/misalignment at the ends can be tolerated?

I'm a bit confused by the specs. It says 179 watts is the max power, which is exactly 110% of the power required to lift 778 newtons at .21 m/sec. This makes sense because the listed efficiency was above 90%.
However, the rated load current draw at 12 volts is 21 amps(252 watts), which is not equal to 179 watts.

I'm trying to get an idea on how the compares to a ball screw/lead screw set up. I'm pretty convinced that for medium loads, this could be a heck of a lot better.