What do you like best?
Sakai is open source and actively being developed. As an open-source solution, Sakai offers academic institutions an opportunity to design their future. Community-driven enhancements, whether from direct development or in partnership with commercial affiliates, allow schools and universities to improve the platform and create innovative approaches to teaching and learning needs. The platform is built on standards and integrates with other tools, especially via LTI. The platform offers many tools. My favorite tool in the platform is Lessons; I love how it allows me as an instructor to sequence content, embed media, ask questions, conditionally release pages and content, and more. I also like the revised Gradebook as of Sakai 11.
What do you dislike?
Since it was originally a patchwork of tools from different systems from multiple universities, there can be some user interface differences from tool to tool. Starting with Sakai 10 and continuing with 11 and 12, the community is actively working together to standardize interface names/features to improve consistency across the platform. So, past review feedback about user friendliness has been addressed and continues to improve in each release.
Recommendations to others considering the product
If considering Sakai, consider attending a community event like the annual North American conference. Meet with other institutions using the platform to learn the good, the bad, the upcoming. From there, consider working with a Sakai commercial affiliate on a pilot so you can evaluate the platform in full. You'll find that the Sakai community is incredibly helpful, so use the community discussion lists and attend events.
What business problems are you solving with the product? What benefits have you realized?
Sakai provide a solid learning management system that can enable the "next generation digital learning environment" (NGDLE) through the use of standards, integrations, and LTI. It's provided a reliable foundation for lesson content, grades, student feedback, class collaboration, and more. Since you can integrate with different student information systems (SIS), you can auto-create class sites for each academic term which makes course management a breeze. With project sites, you can also enable departmental collaboration.