I prefer the friendcodes. They're much easier to typ in, and I never need to know mine from the top of my head. I posted it on this forum, and that's where I'll point to. The numerous times my names has been butchered will attest to the user friendliness of a simple number.
Edit:
To add to that: like someone already mentioned, one problem is people changing their usernames every so often.. I can't remember from some of them who they are on the forum.
And regarding the region thing: generally I don't care what other people do, but it's too much of an hassle for me personally. But I will get pissed if South Africa starts seeing localization efforts that Europe does not..