Hi everyone! Long time lurker, first time poster. Re-posting in this thread as it got little traction previously...
First, a big thank you to everyone on the forums! All of the information has been very helpful! 
I applied for an Amex ED card in July, 2014 after receiving an offer in the mail for 12.99% APR. I was approved with an initial SL of $1000. Since then, the SL has increased, twice using the 3X CLI requests and once with an auto-CLI to $12,000. I pulled the trigger this week and submitted a CLI request and was approved for my requst of $24,000! For me, that makes it the card with the highest CL and the lowest APR. 
My question is this: Should I PC to the BCE/BCP or submit a new app? My spending patterns would support the grocery/gas cash back. My current FICO scores are TU 689, EX 685, and EQ 683.
I'd appreciate any advice!