[The Beast1]

Not to knock the OP's post, but I did a little searching into the Visa/MC exchange rate question. Apparently this isn't cut and dry. Here's a thread I found doing a quick google search on the subject:

http://www.flyertalk.com/forum/credit-ca...-visa.html

It seems that the card type doesn't really matter as FX rates change through out the day meaning what you perceive as a slightly better rate would be caused by the minute differences in fluctuating exchange rates each day.

Personally I have no card preference and tend to use Amex more.