Bests & Worsts Reviews from Amazon

I have been using Frixion pens for years but after pen and after pen would stop working (yes, I put them in the freezer, etc), I got fed up. I ordered another set of Frixion and these ParKoo at the same time. The side by side comparison is amazing. I started using comparable colors at the same time and while I haven't been obsessive, I've used each version about the same amount (to grade papers). The Frixion have already stopped working and the ParKoo are going strong. I hope this keeps up, but I will definitely switch!