I don't know anything about Chase, but I do have an AmEx Blue. I applied through the AmEx pre-app page (which is still offering me a 'preapproved' Blue to this day, although I already have one) in May and was approved instantly, with a $2000 limit. I already have an AmEx Delta SkyMiles and had just had a CLI to $7400, which might explain the relatively low CL.
AmEx pulls Experian - I couldn't tell you what my exact EX FICO was on that day, but I think it was in the region of 670-680ish. My utilization was pretty low, somewhere under 10%, with only one card reporting a balance. My credit history is very short (one year at the time of applying) and the average age of my accounts even shorter.
I was very pleased with the card when I got it, but can't say I've actually used it that much... it's very pretty and all, but in hindsight I'm not quite sure what to do with it! I'm too busy racking up the SkyMiles with the other card, and would far rather have a cashback card of some sort than either of them. Oh well!
If you go for one or both of them, good luck!