After a couple of months in the garden, I decided to see about some SP CLIs today. Started with Discover (~120 days since my last CLI request), got a $1,500 increase for a new total limit of $12,000!
Then decided to give things a try with my Amex BCE--they had rejected my CLI request on activation, citing "not enough history with Amex" as the denial reason (makes sense), so now that I've had 3 statements cut, it seemed like a good time to try again. My SL was $8,800, I requested $17,500, instant approval. I know I could've asked for more, but I didn't want to get too close to maxing out my exposure with Amex since I'm thinking about applying for the ED later this year, and I'm very happy with $17,500!