I agree. You need to know your statistical chances for each option. Your oncologist and that online place can give you recurrence rates and survival rates so that you can make an informed decision.
For some cancers, chemo only gains you a few percentage points, but for others it can mean the difference between life and death. Whatever decision you make, make it with all the information available to you.
You might want to discuss recurrence rates and mortality rates with your oncologist. The website adjuvantonline allows you to input all your information (age, diagnosis, stage, grade, node involvement, etc...) and shows you those rates based on the different treatments you decide.
I can tell you that, given your positive node, you may want to consider the treatment being advised to you. Chemo goes through your entire system and kills cells that are currently present and possibly hiding elsewhere (your positive node implies cancer cells have moved outside your breast) and Arimidex simply helps prevent recurrence. Ultimately, the treatment choice is yours. Good luck to you!