EDIT: I was reviewing credit reports from this past January and they show my Amex limit as $5500. I guess I must have not noticed getting a CLI!
I've never had an auto CLI nor have I ever requested CLI from Amex (Blue/originally apped for Costco use) since opening it in 2005. I just did the online request and went from $10k to $14k as I requested. One of my four total cards is being discontinued so I'm looking to replace that $11k in credit in other places. I RARELY use my Amex, really just for Costco and it's been about six months--time to use again.