That is a tough and close call. I purchased the gray one for my daughter, and she loves it. I did see the black one in real life, months ago, and I didn't consider it, because back then, I thought the 25 size was too small for my needs, and I was iffy on the metal flowers on the bag for some reason that I no longer remember. I think I like the tea roses better in all leather with just a metal stud in the center.
Looking at the side-by-side comparison in your picture, I think they are both lovely choices, and it is very hard to choose one over the other. That said, if the old black and pink tea rose Rogue 25 were still available, I would chose that one over the two in your picture in a heartbeat. I am so bummed that I missed out on that one. As I have the purple Rogue 25, I now know I can wear that bag in the smaller size.