Some significant improvements have been made in the 2nd generation water pump removal tool including:

 

1) It is now made from solid aluminum (versus solid steel) which makes it lighter and less prone to rusting.  

 

2) Previously, the clamps which grip to the front flange of the water pump were fixed, but now they are adjustable to possibly accomodate other water pumps with smaller/larger flanges. 

 

3) And, finally, the tool now has round plates attached to the side extraction screws rather than detached square blocks.

 

Here are photos of the 1st and 2nd generation versions:

1st Generation Water Pump Removal Tool

2nd Generation Water Pump Removal Tool