I have to disagree with a recent WSJ article "When It Still Makes Sense
To Take the Miles". I agree that their might be some point when it makes sense to use miles over cash back, but not based on the numbers they present.
I am not sure their "discounted" trans-atlantic flight is that discounted. The table gives an example of $900 as a discounted fare. I have personally never paid that much and am pretty picky when I fly. I like the morning flight out of Boston on BA so that I avoid the night flights that give you 3 hours sleep (maybe) and get you there at 5am in the morning.
Also, the example for a business class ticket from AA, at $6700 does not factor in two real points.
1. AA does not really have a proper business class (no bed), and
2. It is not too hard these days to get a decent discounted business class or economy plus flight.
In fact, recently, BA had a $199 each way economy plus ticket available. That is a discounted seat that is 7" longer.
The other missing point with points tickets is that you still have to pay for taxes and fees. Once you factor this into the table, I think you will find cash is king and I will stick to my Blue Cash card from AMEX.
Sorry WSJ, but I suspect you have written about this without asking the real question you need to ask and that is for the amount you pay (not the price advertised).