What do you like best?
The Clarizen tool is likely the most configurable SaaS tool available in the PPM world - especially when it comes to the user interface. Meeting a company's need for custom fields & workflows to support unique processes is a major selling point of the tool.
Training and support for the tool is nearly unprecedented - there is high involvement from Clarizen staff to ensure both Administrators & End-Users have the assistance they need to utilize the breadth and depth of the offering in both a highly usable & highly available manner.
I believe one of Clarizen's strongest points of appeal is that it seems to be able to uniquely meet the needs of the SMB all the way up to true enterprise requirements for PMO's.
What do you dislike?
While V6 has brought with it a phenomenal amount of customization of the entire UI, I think there is a need for Clarizen to strike a better balance between providing more pre-configured interface & workflow options for those organizations that don't need that level customization, as it can be overwhelming.
Though it's understandable from the need to "support" the infrastructure (and from a revenue perspective, I'm sure), I think the current licensing limitations on workflow rules, but more importantly custom field creation, as well as the process by which those limitations are "calculated" is a little convoluted.
While mobile app is is fantastics, it's only available for Apple products and not for Android users, so for us, doesn't really provide any value (the supported Android app is the old mobile app and isn't very useful).
Recommendations to others considering the product
Clarizen has a ton of customization, but there a number of things that you'd expect to be able to do out-of-the-box that have to be setup via the customization/configuration settings. That being said, don't even bother with the Professional-level licensing, as you only a get a few customizations.
What business problems are you solving with the product? What benefits have you realized?
The Clarizen tool has greatly increased not only the visibility of projects across our internal organization, but has been able to allow us to provide better, more consistent project visibility to our customers as well.
Having a single place that is accessible on-demand for managing projects across our team has been a huge gain in efficiency.