These are just my random thoughts on the subject and nothing more. Some of it may be right and some may need correcting.
Proactive was Brunswick's name for their particle coverstock. In future versions, they varied the loading process and would have names like DTX-4,etc. to identify the changes.
Some of the high load particle balls were the Pro Zone HPH, the Swamp Monster, and most recently the Goliath. Some of the low load particles were the Pro Zone HPD, the Fuze Eliminator, and the Impulse Zone. Pearl particle balls included the Raging Inferno and the Ambush.
Particle technology gives the ball a little earlier breakpoint and a lot less jumpiness on the back. Older players will think of the ball motion as an old urethane-like reaction with a lot stronger hit at the pin deck. Pearl particles seem to be more popular because of the control aspect and any serious tournament arsenal should have at least 1-2 included.
Comparing particle to reactive is not to tough. Reactive tends to be more stronger in the midlane and the backend. Particle will grip the lane earlier and tend to "lay off" in the backend. A good time to think particle is when you feel you are in the right spot for good carry and the ball gets jumpy on the backend affecting your pin carry (slam tens,fours and nines). This is a good time to try a particle pearl out in the same area and see if you can get it to "slow down on the friction".
Of course, you have to know when to use them and when to put them away. That will only come from practice and recognition of the ball motion on the pattern on the lane.
