I can tell you why not to choose DC.

I've been a DC card holder for 10 years and have been very happy with the level of service, lounge availability and acceptance all over the world. Until now that is.
Since the change of ownership last year I've had major issues trying to get cash from ATM's. When travelling I've always gotten cash from local ATM's rather than having to waste my time in foreign exchange offices prior to my trips, it's just less hassle that way.
But now, even in my hometown in Stockholm, Sweden there are only of handfull of ATM's that will accept DC. I went to Dublin, Ireland over Xmas and not one single ATM would take my card. After 4 calls to customer service I finally got told that Ulster Bank would issue me cash.
Well after the third different Ulster bank turned me down because it wasn't an Irish card and they knew nothing about it I gave up.

So what did I do when getting home? I of course contacted customer service to complain, telling them the story. Now I'm not the kind of person that goes off on a rant at customer service people or expects red carpet treatment, but I do expect a certain kind of acknowledgement to the problem and a bit of sympathy in my predicament for a paying customer (a very well paying customer I must add).
Instead I get a "Yep, we've heard about the problem but there's nothing I can do for you". I asked if DC are in any way shape or form concidering any form of compensation (e.g reduced annual fee) to help smooth things over until things get sorted? "No, why should we do that?" was the answer I got.

So that's that then. My business with DC is now over and I'm going over to Amex, maybe they will like my hard earned cash better.
Last year I had approx. 150 travelling days, in previous years I've had 2-300 days, and always used my DC. Not anymore.

As a foot note, I haven't been to the US since the change, maybe the ATM issue isn't as apparent there. But here in Europe it's gone completely pear shaped.