Hi Karen,
As you know I'm sure they are sister drugs with very similar side effects although some people find one easier to tolerate than the other for some reason but you may not know that without trying them out.
I began taking Arimdex in September 2006 after my (preventative) ooph, within weeks I did notice some joint stiffness and trigger thumb so my Onc said to take Glucosamine/Chondroitin which helped a little although you need to be taking it around six weeks to notice a difference.
Seven years have passed since then and some of my side effects like Trigger thumb have eased but I still have the joint stiffness which is usually worse after sitting for long periods but doesn't prevent me doing my daily 6k walk. I've agreed to continue taking this up to ten years as my Onc feels the current trials are looking promising and I prefer these minor side effects to a recurrance any day!
Good luck with making your decision and hope you do well on it.
