Has anyone here decided against taking Arimidex?

My onc switched me to tamoxifen. There are studies that indicate that switching from an AI to tamoxifen after two years affords similar protection to the full five years of AI. My joint issues are much reduced and, while I was ready to ditch the AI, I now feel I can make it all the way to five years. Five years in my case, is rather longer than for some--I took so many drug holidays on the miserable AI, that I have several months of non-drug to make up for.