Pretty much when it comes to jug pets the situation at endgame is always the same.
Carrie remains the only affordable jug that's uncapped. Anything else you'll basically be looking at paying at least as much *per jug* as a stack of Carrie costs. In some cases you'll be looking at paying 10x what a stack of Carrie costs for a *single* jug that lasts up to 15 minutes.
Then even at best, it'll pale next to even a DC charmed mob. Plus, even if you were inclined to spend 100k-1mil on HQ CoP pets per event, finding them in stock on the AH would be difficult.
Now, if you drop to say, doing CoP missions in capped zones, then there's a discussion to be had =P
Actually, it's worth mentioning that fully meritted, a Fungaur jug will probably be the weapon of choice. It's cheaper than Carrie most of the time (from NPC, not the scalpers on the AH), hits harder, has better TP moves, etc...and caps at 65 :/
Depending on how low Carrie is called at, and whether or not 65 is a guaranteed level for Funguar at 75BST, things may be somewhat interesting.
Though the point would likely stand that due to precedent, most BSTs will likely just change jobs for those kinds of events.
Still, IMO, BST is the job in most need of fixing, except PUP.