Today I upgraded our demo server from version 11.0 SP3 to SP5. Service Pack 4 added support for Firefox ESR 38, and SP5 adds support for Windows 10 as a client. View the Aras PLM Roadmap here.
SP5 also added Aras Visual Collaboration, an advanced PDF viewer, but it requires a license and I haven't installed it yet.
You must be an Aras subscriber to get service packs, and Aras will help subscribers with upgrades. I recommend this if you are on a production environment.
The documentation included in the SP5 CD Image is excellent, simply follow the 12 pages of instructions step-by-step to succeed. You should allocate about 3 hours for this upgrade - more if you support multiple databases on your instance like I do. It requires upgrading each database with the Package Import-Export Utilities, which takes about 10 minutes per database.
After the Aras Innovator upgrade, I *finally* upgraded my Firefox client to the ESR 38.5.2 version (Extended Support Release). After allowing Firefox to install the Aras plugin, it worked fine - and I no longer have to suffer the notices telling me to upgrade my old ESR 32 release. IE11 also worked fine after installing the .NET controls as Aras describes in their documentation.