UI is pretty snappy and is reasonably good at updating without reloading. Story templates are nice, and the new code/qa review options are a nice move.
It is a very reliable program with great backing (customer service support) and detailed processes that are easy to follow.
I love how simple estimates are on stories, how it tracks velocity, how easy it is to use and it's a great price point for my business.
Pivotal tracker User experience is pretty terrible, only has a cardwall view. It was hard to find information.
Incredibly slow and laggy to the point of hurting team productivity.
It's hard to keep track of what you are assigned to across different projects.