The biggest problem I had can be summed up as simply "eCredits."

Now that you can change or cancel flights without fees it's not hard to end up with piles of eCredits even if you're only re-pricing your tickets over time. Now throw in the probability that the more you travel the more your plans tend to change and it's not hard to end up with a bouquet of credits that all have varying expiration dates.

I don't have the card anymore, but I'd rather add another eCredit to the pile of eCredits I'm already working with than having to deal with a separate Capital One credit that can't be combined with any of the airline credits I'm already holding.