FWIW, AMEX has been good about not pulling or at least soft pulling. Over the course of time, I've increased my SPG and HH Amexs from around $8k to over $30k without incurring any credit hits. I spend a lot and payoff every month, before I used to pay off multiple times because I'd regularly exceed the $8k limits. I had a couple stops between 8k and 30k on each card, but never had a pull. The disclaimer does mention a credit check possibility if I recall.