*laughs*
The great varying answers in this thread have proven entertaining, I??must say.
I believe my favorite was the one on rates.
Personally, I believe Aaronock's post provides and most correct and indepth set of answers.
The best way to describe the effects of MvP cards wouldn't necessarily be by saying "They work everywhere" or the such. They aren't customised. They work "officially".
Population is actually quite seasonal, majorly influxing during the NA summer holidays, and reaching the lower end during Thanksgiving/Christmas times and exam/finals weeks.
On the point of GMs, several of them work more behind the scenes than others. They're not all as big a attention hoggers as I am.
Whichever server your guild chooses, we wish you the best of luck.