I just got one from PBL about a week ago. For anyone who has a need for this tool and never bought one, let me say that I have been really glad to have grabbed one. Adjusting switches is so much easier and more precise now. I have a Williams Space Odyssey EM and I recently completed a flipper rebuild using a kit from PBR. My new flippers felt about the same as the old ones did in terms of power to move the ball up the table until I used this tool to fine tune my new EOS switches. I can't believe how well the flippers work now. The tool made a huge difference. I had been using needle nose pliers to do this previously but these tools are better and make it so easy to adjust switches very precisely. I could make adjustments with the needle nose but the adjuster tool is much better in my opinion. I'm sure some will say that needle nose work just as well once you really learn how to use them for his purpose, but I just find the tool so much easier. The adjuster tool from most places also has different bends on the two ends so that you can work in the confined spaces commonly found in pinball machines. Big bonus there.
Also, they enable you to make your adjustments down low on the switch where the leaf meets the switch stack which reduces the chances of breaking the leaf.
I also used the tool to fine tune my pop bumpers. It was very easy to adjust them to a point where they are now extremely responsive. It took a little time and patience to go through the process of really dialing them in, but once I was done I could not believe the difference in the operation of the pop bumpers. They are so incredibly lively (full disclosure - I rebuilt the topside components of these as well and thoroughly cleaned the underside components). Everyone who has played the table before and after this adjustment has been really surprised by the difference.
I'd say it was well worth the $8.99 I had to spend on a leaf adjuster tool. Get one and find out for yourself!