I have yet to use the Polar Pure. By far this is the most cost effective way to use iodine, the crystals last forever. This year a group of americans came down to visit me and brought me about 10 packages of Potable Aqua Plus so I'm in no rush to go buy iodine products.
When I run my course I teach them how to use 2% Tincture of iodine available in local pharmacies for about $.50 a bottle. Five drops per liter, double if needed, wait at least a half hour, or double if needed.
I do that mainly because part of what I do is to teach them how to use what is sold on the market here rather than give the impression that they need to buy imported kit.
There is an old product that recently made a comeback here that is very good. Clor-In 1 is sold in 30 pill blister packs. Each pill treats 1 liter of water with chlorine and it only costs about $1.50 per pack. I find people don't object to the taste as much as they do with iodine. The water treated with chlorine smells like a pool rather than a bandage. It also fits in my mini-kits better so I've been using that recently.
I start my guys out with the iodine drops and then later let them switch to the Clor-In 1. They always get mad at me for not showing them the Clor-In 1 first. Mac