I use PS cause I can find it anywhere. And it does what it's supposed to. I can definately tell when I haven't been using it. Truck seems to have the same power, but is noisier (if you can believe that). I also lose about 1-2 mpg without the stuff. Hardly a justification of the cost, but I need the added lubricity. The other stuff is just gravy.
There are other fuel treatments that are better (IMHO), but there is nothing wrong with PS at all. I use the white bottle all year long. I should switch to the grey during the summer, but I never do.
As for carrying a spare filter, that's excellent advice (I never thought to mention that before). If you go on a trip and get a load of bad fuel, then a spare filter will make getting on your way a much simpler task. Or if you do happen to gell your fuel, replacing the filter will almost be a must.
\'99 2500 ISB QC SLT (No Leather!),4x4,5sp w/McLeod,4:10,BP8x11\'s,B-1,FMS,EZ,PE4200,LPG,H2O/CH4O,4\"exh.,Pac-Brake,OBA,more switches than you,Line-X,V-1,lts,siren,lic. plt. frm says \"<b><i>Diesel Fumes Make Me Horny!</i></b>\",and much more goofy stuff.