Also remember this cards goes at 1:1 ratio in BA. So this card in my option is better than Chase BA card as Chase card has annual fee of $75 and Chase never runs any type of bonus like Diners or Merrill. So spending $50K on Chase = 50K BA miles while if you spent $50K last year on Merrill you got 60K BA miles and +3 benfits to boot. While Diners would have gotten you 75K BA miles but no +3 benfits for $85 annual.

So as you can see Merrill is better than Chase's own BA card and it is a toss up between Diners and Merrill in my option depending on what is more important to you the miles or free lounge access.