Congrats! I still haven't managed to unlock that store and I've no idea how much long it'll take as I've lost count of how many times I've visited their tent. ^^;
Congrats! I always hoped that getting Katrina out of the way on Main Street would make other special guests like achievement and Sahara show up more often. I don't know if it's true, but enjoy the achievement!
I've got it, but I never even use it. I just got it to complete my main street, and so I don't have to worry about Katrina's tent showing up and crushing any items I have in the plaza!