I think for the amount of effort to get to level 20 the following should be given:

1) A really cool, unique barding (Getting the other two specialty bardings is lame)
2) The Chocobo should get a special skill that is on cooldown and used like the SMN pet specials. ie. Chocobo Flare
3) The Chocobo should get the ability to turn into Bahamut, fly you around on its back, and one-shot S ranks.