I have all my pets upgraded to Adept 3, and it is worth it.
I use the tank pet only when taking out tough mobs, or when taking agroups of ^ or ^^, or single ^^^. I use the the air pet for almost everything else, getting high DPS with good survivability.
The mage/fire pet stays in the pouch unless I'm in a tight group with a solid tank and other DPS. Otherwise, it pulls agro too much and dies, dumping all the agro on me. A nice trick SOE gave us. :(