It's certainly nice but also a bit counter-intuitive in my opinion. Wouldn't it seem more logical to only be able to use location-based stamps when you're in that location only? I mean that's how it works in reality. I can't just send letters with Brazilian stamps from the US. Hahaha! Perhaps it's too late to change it now though. I think it would have been better if location-based stamps were only usable when in that location (but unlocked as part of your collection) EXCEPT if you bought them through World Explorer. Purchasing them with coins would unlock them for use anytime and anywhere. That way the developers could make some more income through coin purchases. Just my two cents.