Improved Master 1 teardown
In this image, you can see how they've made it harder to shim - the locking pawl can't be easily pushed back with a shim, and the slot in the shackle is square, so it's not easy to get anything in there.
Here, the rivets are inset, so it's harder to get to the bottom of the rivet with a flat file.
The actuator has been modified so that the bypass tool won't work anymore (I think)
I think that some cost saving measures have been implemented too - rather than use a C clip to hold the cylinder in place, the case has been deformed to hold the cylinder in.
After I got the cylinder apart, it doesn't appears as though there were any security improvements there. The top pins were all the same. There were low pins and high pins, and I couldn't get it open with 2 seconds of raking like I saw in a youtube video, but it was still easy to open. I should note that the finish on the pins wasn't the greatest either.
Sadly, their improvements have not made the lock resistant to rapping - I could open the lock with a hammer and a piece of chain. I didn't have any bold cutters handy, so I couldn't check cutting resistance. So it's better, but not great.