With less than an evening of using tumblr I already have a pro and a con to using it. The con is I was actually using the mobile app to create my first post. At some point I switched to gchat or Pandora on my phone and when I went back to tumblr I got the splash screen. It was news to me that the tumblr app was actually closed at all, but when I saw that screen I knew all the text I had typed out on a software keyboard was likely lost. Sure enough this was confirmed when I looked in the drafts and had none.
This will probably never be an issue again since I will be saving drafts BEFORE switching apps from now on, but, it was annoying nonetheless.
The pro was that while I was looking at the source of tumblr I saw they have ASCII art at the top of their pages. Which obviously is super win in my book. Well done, tumblr.