Linux Mint's default mode of upgrading from one release to another is a mix between a real upgrade and a fresh install. The installer will leave the home directory partition intact while it wipes the system partition and re-installs the system partition from the live image. This will, in most scenarios, give users a quick install of the new release while leaving their user data in place. This method has, however, some downsides, especially for users who prefer to use their own partition setups or who have customised their systems heavily. For a long time, the Linux Mint developers used to promote this upgrade method and actively dissuaded users from doing package-based system upgrades in the style of Ubuntu. In the past, this was a good reason not to recommend Linux Mint to some users, as an atypical partition setup coupled with a lack of recent backups could lead to disastrous results. While the Mint developers still recommend this method, they now also officially support package upgrades with APT. They say this upgrade path should only be used by experienced users, but in testing at The H, a distribution upgrade with APT performed as expected and worked just as one would expect on a plain Ubuntu system.
One important point to keep in mind is that Linux Mint currently does not work at all with systems that use UEFI firmware and have Secure Boot enabled. The Mint developers recommend users turn this function off completely, which can be easily accomplished but also means that users of Linux Mint will not enjoy the additional protections of signed kernel verification that Fedora, openSUSE and Ubuntu offer. If Secure Boot is disabled, Linux Mint 15 should work with UEFI firmware in general, but the Known Issues section of the release notes lists some problems with certain UEFI setups that also surfaced in testing at The H. The developers recommend some steps users can take to work around these issues or users can simply switch their systems to enable the Compatibility Support Module (CSM) or "legacy mode" in their firmware, a measure that helped cure our boot problems at The H.
Linux Mint 15 is a very solid release that further improves on Linux Mint's own look and feel, especially in its Cinnamon version. With the Canonical developers being busy getting Ubuntu to run on phones, tablets and TVs and, to some degree, neglecting to put new end-user-visible features into the desktop version of their distribution, Linux Mint seems ready to step into the breach and present a version of Ubuntu targeted with its full might at the desktop. With its own desktop shell, file manager fork and system management tools, Linux Mint is one of the few Ubuntu derivatives not sanctioned by Canonical that adds its own character and noticeably sets itself apart from the distribution it is based on. While the new features in Olivia are mostly relatively small additions, the polish that these contribute further increases the shine of a distribution that already has a good reputation. The new package and driver management tools work well and rival, if not exceed, comparable functionality in other distributions. The Cinnamon desktop environment has steadily improved with every release and is now a very solid contender to GNOME Shell, Unity and KDE's Plasma desktop.
When Linux Mint founder Clement Lefebvre proudly exclaims Linux Mint 15 to be "the most ambitious release since the start of the project", he might just be right. The Linux Mint project, now in its seventh year and wholly backed by donations and sponsorship deals, is not only shouldering its own distribution packaging work but also the development of a full-blown desktop environment and their own system management tools – and the developers show no signs of slowing down. With its latest release, Linux Mint takes a further step towards becoming the destination desktop Linux for new users and tinkerers alike.