The only disadvantage to PS3 version is the possible delay in getting player made add-ons. On PC you can download and add them as soon as they are ready, but I guess SE would have to port over the add-ons (of their choice) to the PSN first.

In FFXIV you could both rent chocobos and eventually through the Grand Company quests, you could obtain and name your own personal chocobo. The rentals were a little slower in speed though, and had a timer on them. You can summon your personal (grand company) chocobo whenever, and for however long you wanted.

You can own more than one, we had the GC Chocobo and a Goobbue mount that was only available to obtain for a limited time. So the Legacy Chocobo would give some of us 3 mounts.