Originally Posted by wanaflyforless
If you never need expensive tickets a fake miles card is good - I would recomend the MBNA one. If you sometimes need expensive tickets, miles present a better value.
Equally important: If you only use miles for tickets, a fake miles card might work.
If you use miles for other things (most obviously upgrades, and at least with AA for lifetime status*), then a fake miles card is probably pointless.
(*AA lifetime Gold is 1 million miles from ANY sources, lifetime Platinum is 2 million miles from ANY sources, and ANY source obviously include credit cards. Most other airlines -- but I don't know about Delta specficially -- either don't have lifetime status or only count in-the-seat miles towards lifetime status.)
And, btw, if you use miles for only VERY CHEAP tickets, a fake miles card is also likely to not be the best value (a cashback card might work better in those cases)!