Ulysses and Drafts are both extraordinary apps. They each sit at the top of the heap of iOS Markdown editors, offering unique strengths that may appeal more to one type of user or another.
I'm a fan of Drafts, in fact, I'm using it to publish this link. I've tried Ulysses, it seems like it could be a very good tool for those who write a lot, but I don't and I found a few things I didn't really like about it. Each to their own, right.