I remember when I first played FFXI back in the day, I didn't get a choice of worlds, I got bunged on Odin, I didn't realise how much this meant to me... When I re-created my char, I started On Odin.. remembering that I did have some help, when I first gave it a bash.

Odin.. for me.. is the best world, I have been on Fairy (when they closed Odin) which got merged to Sylph, I went back to Odin soon after the merge...

However Odin, is getting merged with Ifrit soon (Ifrit > Odin) which.. funilly enough, were both my fave summons in FF7

So in short.. I dont think it matters what world you are on, as long as you make the most of it, I have created chars on other worlds with additional content ID's and have found that, there are a LOT of friendly players out there... which is rare for MMO's