One of the major new features of elementary OS is their new Open Source App Store.
Loki is being built with the Ubuntu 16.04 LTS repository, which means it comes with Gtk 3.18, Vala 0.32, and Linux 4.4 as well as a multitude of other updated libraries. Loki also removes Ubuntu's Ayatana with a brand new set of wingpanel indicators for a better experience.
From their website...
"elementary OS is Open Source... Our code is available for review, scrutiny, modification, and redistribution by anyone. We dont make advertising deals and we don't collect sensitive personal data. Our only income is directly from our users. elementary OS is Safe & Secure. We're built on Linux: the same software powering the U.S Department of Defense, the Bank of China, and more"
If you want an impressive, beautiful and snappy linux desktop based on Ubuntu, give elementary OS a try.