There are people who could easily get bored of the samething... That is always why they make more. If you play with it the same way each time... well ya. The connections (To me) seem like they are almost never the same...
Like the v4/v4.5, different jobs you can choose from, different characters based on those 3 main points in the status... that sort of thing. I wouldn't get bored of that one for sure just because of the numbers and different ways you can get different characters....
Its all in the way you care for your tama and how often you really play with it.