I find pivotal tracker to really be my sweet spot amongst all these offerings. Maybe I just didn't know how to use it but Trello seemed a little too simplistic. What do you like about Trello vs. PT?
Not the OP, but I found that PT has too much friction to create a task. Trello is much easier -- just type and press enter, then type another task and press enter, without even touching the mouse. I found that the friction of PT made me remember things in a mental TODO list, or Google Keep, or Inbox. Maybe it's not rational or "correct" but when tools have friction, we seek out simpler alternatives even if we know we're not supposed to do that.
The other problem with PT is that it promotes a bottom-up view of your project rather than a top-down view. You end up missing the forest for the trees. With Trello, I can create a list for a high-level goal like "Validate that users want the features we're building" and then list sub-tasks within that.
