My Platinum Delta AMEX card is about to come up for renewal. I have a Capital One Go Miles Card as well. I am thinking that since I don't use the Delta free companion ticket each year, there is a better card out there for general travel, specific hotel chains, cash rebates or whatever. Any suggestions are appreciated.

PS. I really like AMEX customer service, especially for Internet charging, but wonder if Delta miles will become worthless as time goes by.