Sorry, what was your question? Your tagline image is so large I can't see it.
But seriously, I think it depends on what you are looking to do (PvE or PvP). Xu-Fu has alot of possibilities in the PvP realm, or so I have heard (I've still done almost none). I haven't really tested out Xu-Fu or Chi-Chi against the tamers or Beasts of Fable, though.
Chi-Chi would be great against mechanicals (Wild Magic + Fire Quills), unfortunately there are not many of those in the tamer circuit (unless you like to go to Outlands for 19 gold in Hellfire Peninsula or the like).
Xu-Fu for levelling is not really as good as Gahz'rooki because his Prowl/Feeding Claws has too long a CD. Zao is in a similar boat - huge heal but the delay is too long for using it (perhaps) to be useful. They can both hit hard but might get hit too much to be as sustainable as Gahz'rooki (or the Molten Spider I use as my backup).
Yu'la would probably be excellent for levelling pets against a flying team. She's not as good as an emerald proto-whelp for the tamer circuit as her anti-flyer attack is an AoE.