After having played vanilla WoW & TERA, I decided to make it a rule to not play any MMO until it's had at least one expansion, just to ensure it's not a dying game (sup TERA), or buggy/lacking content to start (hi crashing WoW servers).
It also gives the game enough times for players to come up with a general consensus if this new MMO (not XIV, but new MMOs in general) is just another case of "grass is greener on the other side" or not, since beta perceptions always tend to get inflated, like it did with TERA for me, that was a really fun beta, until retail hit and you finished everything in two weeks.....
God damn, why did TERA's battle engine have to get wasted on TERA? XIV's feels so boring in comparison with its 2.5GCD.