After reading the other thread I am a bit curious about this and how it is working out for others. We don't have it on as it seems a little out of sync with my impressions of regional buying power.
The latest version of the Big Mac index I could find is:
http://www.economist.com/blogs/daily.../big-mac-index
The 1 to 1 ratio for EU at CCBill seems a bit high and I am wondering if customers would back out of the sale at this ratio?
Is it possible to switch it on for only some currencies? That would be really nice.