Reed 3P, as well as it's predecessor Reed 2P, is equipped with Fast VTA (Vertical Tracking Angle) adjustment feature. Of course, Reed's VTA can be changed using fine VTA adjustment knob on the top of the tonearm base, so one may ask -- why is that extra "Fast VTA adjustment" handle is needed? The idea behind Fast VTA adjustment is that human senses (in our case - ears) can determine peak performance only if something changes fast. If changes occur relatively slowly, they adapt to "current" situation and it's not easy to tell the difference between the starting situation and the ending one.
Fast VTA handle allows changing VTA quickly, so that listener could be able to tell if he sensed the best sound in the given VTA range. For example, with 9.5" tonearm and using Fast VTA handle you can quickly change VTA by 0,95 degrees. In comparison, one full revolution of fine VTA knob will change VTA only for 0,36 degrees, i.e. it will take more than 2.5 revs to get the effect of single Fast VTA handle movement.
So for people, who adjust VTA based on their ear, Fast VTA adjustment handle will help to do that easier and faster.